Highlights From The Last Twenty Years Of Political Theory

I would suggest as examples of the most notable developments in political theory in the last twenty years, the points below, in two broad categories and no particular order. 
To be clear, I am not endorsing any of these articles as correct. I am simply summarizing the state of new developments in academic discussion in the field in the last twenty years so that others are aware of them.

National scale success, conflict and war

• In the wake of 9-11 there has been lots of serious and academic analysis of the nature and causes of terrorism. The modern trend is to view it as a form of asymmetric warfare and to recognize that most terrorists see themselves as patriots and heroes rather than being amoral monsters. See Kenneth M. Pollack; A Path Out of the Desert: A Grand Strategy for America in the Middle East; Random House; New York: 2008; pp. 173 and 175; Mohammed M. Hafez; Suicide Bombers In Iraq: The Strategy and Ideology of Martyrdom; United States Institute of Peace Press; Washington D.C.: 2007; p. 8. There has also been acknowledgment that while there are instances of both left wing and right wing terrorism, that terrorism is much more strongly associated with conservatism and that terrorist are often oriented towards thinking about things while having weak social skills (e.g. engineers are much more likely to become terrorists than literature majors).
• There has also been serious attention to anti-terrorism tactics that are perceived as "tough" on terrorism but are not actually effective at stopping it. One such case is the literature showing that "harsh interrogation tactics" and torture don't work nearly as well as tactics oriented toward getting people to let their guard down (like taking a mass shooting suspect for a sandwich at Burger King to encourage him to confess). Another case in point is the much wider recognition of the notion of "Security Theater" which creates the perception of doing something by inconveniencing lots of people even though it isn't very effective (like removing shoes in airport inspection lines). See "Against Security" by Harvey Molotch. See also Robert M. Chesney (University of Texas School of Law) "Iraq and the Military Detention Debate: Firsthand Perspectives from the Other War", 2003-2010. Implications of asymmetric warfare for both insurgents and empires has received much more attention with the focus on the questions of what wars make sense to fight and how to do so when you must.
• There has also been a trend towards disavowing the doctrine that words are harmless spawning concepts like stochastic terrorism.
• The Treaty of Westphalia's notion of an international obligation of nations to respect each other's sovereignty has been eroding on multiple fronts that are said to justify intervention in activities in the interior of other countries in the last twenty years. This ranges from human rights abuses, to recognition of the global impact of the economic policies of individual countries in a global economy, to recognition of the impact of the international drug and arms trade and poor domestic policies of other countries on refugee problems, to the recognition that in an age of long range missile and drone attacks one's own country can be deeply at risk well inside its borders from activities well inside another country's borders (e.g. weapons of mass destruction were justifications for the Iraq War and weapons of mass destruction and human rights were justifications for military intervention in Syria). The concept of a "failed state" has also gained more currency.
• Scholars has developed a better understanding of why the Presidency is so powerful on national defense matters. Aziz Rana (Cornell Law School) "Who Decides on Security?" (Connecticut Law Review, Vol. 44, No. 5, 2012).
• There has been some academic literature seeking to revalidate the previously unpopular and largely discredited notion that national boundaries and ethnic segregation that align a country's boundaries with a culturally defined people which critics of nationalism argued merely involved a manufactured since of identity really does reduce war and political conflict and makes countries function better politically. See "Good Fences: The Importance of Setting Boundaries for Peaceful Coexistence" (2011) by Alex Rutherford, et al. In accord with this sentiment, subnational autonomy and independence movements in places like Scotland and Catalonia have surged in the last twenty years and the occupation of Ukraine and seizure of Crimea by Russia has spurred only a little international reaction. See also "Divide and Rule or the Rule of the Divided? Evidence from Africa" by Stelios Michalopoulos, Elias Papaioannou, NBER Working Paper No. 17184 (June 2011) (economic development more closely tracks ethnic group populations than national boundaries of governments able to set policies in Africa).
• There has been a lot of research on the political impact of cousin marriage and endogamy within related groups like tribes and jati (i.e. fine grained caste groups). Cousin marriage and closely knit more remotely related tribes and castes tend to lead to weaker and more corrupt state institutions. See Mahsa Akbai, et al., "Kinship, Fractionalization and Corruption" (October 3, 2016). Several newly released think pieces attribute the economic rise of Europe and the West to the Christianity enforce ban on marrying people closely related to you, at a time when states were otherwise weak. See, e.g., Joe Henrich, "The WEIRDest People in the World: How the West Became Psychologically Peculiar and Particularly Prosperous". In a related point, there has been increasing recognition that the "state of nature" (e.g. in Afghanistan and Somalia) is not atomistic anarchistic freedom, but instead systems of clans and tribes with family ties to each other led by chiefs who force members of the clan and tribe to subordinate their personal freedoms those of the group. See, e.g., Mark S. Weiner, "The Rule of the Clan".
• More generally, the literature on what makes societies thrive and fail in the long run has received more attention, with climate, contagion, geography and economics based theories growing competitive with culturally based theories. See, e.g. Tarko, Vlad and O'Donnell, Kyle W., "Escape from Europe: A Calculus of Consent Model of the Origins of Liberal Institutions in the North American Colonies" Constitutional Political Economy, Forthcoming (June 19, 2018).
• Evolutionary biology and new ancient DNA findings showing that population replacement was more common relative to cultural diffusion than previously believed by mid-20th century anthropologists has encouraged conceptualizing events in terms of "culture group selection" as a frame for the U.S. culture wars and other conflicts, in a modern group oriented take on the social darwinism of the 19th century.
• It was once a widespread assumption in political theory that economic growth and political and democratic freedoms were necessarily linked. The experience of China in particular, but also other Asian countries like Singapore, has deeply shaken that truism in democratic theory. Similarly, in the 1990s shortly after the demise of the Soviet Union and the fall of the Berlin Wall, it was widely believed that democratic capitalism was the inevitable path towards the future. See "The End of History and the Last Man" (1992) by Francis Fukuyama. But dissolution of large swaths of people in developed nations with the democratic process which many perceive as captured by "the 1%", the less than idyllic democratic systems that have arisen in Eastern Europe after the fall of communism, mass preferences for Islamic states over Western style democratic states in much of the Islamic world, the political instability of many new democracies resulting in ugly insurgencies and civil wars, and the East Asian experience have all fostered increased interests in alternatives to Western style parliamentary democracy coupled to free market capitalism, including non-democratic regimes by intellectuals on both the left and the right, and has led to pessimism about the long term prospects of global political economies. See, e.g. The Democratic Disconnect by Roberto Stefan Foa and Yascha Mounk, Journal of Democracy Volume 27, Number 3 July 2016. Views on the prospects for the human condition's future and human nature are not universally negative, however. See Rebecca Solnit, "A Paradise Built in Hell" (2017) and "The Better Angels of Our Nature: Why Violence Has Declined" (2011) by Steven Pinker.

Political identity, electoral politics and movement politics

• While identity politics was alive and well in the late 20th century, the foundation of evidence supporting the existence of systemic racism in the criminal justice system in particular has grown much more solid and been much more widely accepted. Similar developments have been made in other areas (e.g. environmental racism). For example, within the progressive movement there has been an increasingly widely held view that it may be appropriate to subordinate some classical liberal personal freedoms to the cause of racial justice. See, e.g. “Occupy Liberalism! Or, Ten Reasons Why Liberalism Cannot Be Retrieved for Radicalism (And Why They’re All Wrong)” (2012) by Charles Mills. Others have questioned the virtues of naive meritocracy and note that nepotism shows up in unexpected places (like professional basketball, journalism, acting, and military service). The notion that technology is not necessarily ideologically neutral has gained more recognition. See, e.g. "Automating Inequality: How High-Tech Tools Profile, Police, and Punish the Poor" (2017) by Virginia Eubanks. Another development of this literature has noted that race and ethnicity strongly influences which socio-economically successful people are likely to see their children fall in status and which socio-economically struggling people are likely to see their children rise in status. See, e.g. “Race and Economic Opportunity in the United States: An Intergenerational Perspective” (2018) by Raj Chetty, Nathaniel Hendren, Maggie Jones, and Sonya Porter. New research also has determined that the voting reforms of the civil rights era led to different electoral outcomes than in turn resulted in different policies that in turn improved the well being in many domains of people who had previously had voting rights impaired by policies that civil rights era legislation removed. See, e.g., “Valuing the Vote: The Redistribution of Voting Rights and State Funds following the Voting Rights Act of 1965” (2014) by Elizabeth Cascio and Ebonya Washington. These developments have also led the counter-movements. See, e.g., "White Backlash: Immigration, Race, and American Politics" (2015) by Marisa Abrajano and Zoltan Hajnal.
• The marijuana legalization movement and decline of the "war on drugs" didn't originate in the last twenty years, but has made immense strides in that time period, achieving partial or full legalization of marijuana on a national and international scale and dramatically reducing the criminal sanctions for drug crimes in lieu of a more public health oriented approach (Switzerland, Portugal, Colorado, Washington State, and California were leaders in this area). This has been fostered, in part, by recognition of the problems (which are not precisely racial but are not indifferent to racial injustice) of mass incarceration in the U.S.
• The first official recognition of same sex marriage as a matter of policy was in 2001, driven by an evolving understanding of what being lesbian, gay, bisexual, transgender, etc. has caused recognition of same sex marriage to be constitutionally required everywhere in the United States as a result of Obergefell v. Hodges (U.S. 2015), and widely adopted in much of the world.
• Changing attitudes towards the nature of marriage and love have cast polygamy in a new light based upon new political understandings of it has resulted in many people seeing the practice as sometimes problematic but not universally to be condemned. Hand and hand with the new political focus on consent and freedom to choose who you love that gained new attention in the gay rights movement have been movements to end marital rape exclusions (that have largely run their course), movements to elevate of seriousness with which sex trafficking and prostitution involving minors is seen, and opposition to marriage of females who are minors based upon the perception that such matches are not truly voluntary.
• The means by which political identity is established and changed has been the subject of new thinking. There has been a lot of development in understanding that the model in which people form political views (and change them) based upon a rational analysis of evidence presented to them is inaccurate and misleading. Instead, political views are to a great extent a function of a larger wold view and are more strongly influenced by interpersonal social interactions, by the realities associated with the population density and ethnic diversity of the places where you live and work, etc. The modern view is to look for the same kind of factors that influence religious conversions and language shift. See, e.g., Daniel M. Abrams, Haley A. Yaple, Richard J. Wiener, "A mathematical model of social group competition with application to the growth of religious non-affiliation." There has also been increasing recognition that the cultural and political views of a founding group in a geographic area are very persistent over time even in the face of moderate rates of immigration of people who are assimilated to the founding groups culture and views. Research on the attitudes of people towards vaccination has been some of the ground breaking research in this area. Also along these lines new data has tended to convince political theorists that rather than getting gradually more conservative as they get older, people tend to imprint a set of political attitudes at the time they become politically aware that remains more or less stable over the course of their lives. The finding that when 25 percent of people in a group adopt a new social norm, it creates a tipping point where the entire group follows suit, showing the direct causal effect of the size of a committed minority on its capacity to create social change, has also influenced how political theorists think about movement politics. See Damon Centola et al. "Experimental Evidence for Tipping Points in Social Convention." Science (2018). The intersectionality, for example, of race, foreigner status and gender has also been a hot topic upon which ideas have been evolving. See, e.g., Navarrete et al. Fear Extinction to an Out-Group Face: The Role of Target Gender. Psychological Science, 2009; 20 (2): 155.
• The Dunning-Kruger effect was formally described in 1999 and has gained widespread acceptance as an explanation of political behavior. A related investigation in political theory has been analysis of the circumstances under which thoughtlessness and ignorance is "mostly harmless" and those under which it can have pernicious consequences. See, e.g., “Cluelessness” (2016) by Hilary Greaves. Sometimes, for example, leading democratic theorists have argued, even ignorant participation in the process produces desirable outcomes. See “Democracy for Idealists” (2016) by Niko Kolodny. Accord here and I. D. Couzin, C. C. Ioannou, G. Demirel, T. Gross, C. J. Torney, A. Hartnett, L. Conradt, S. A. Levin, N. E. Leonard. "Uninformed Individuals Promote Democratic Consensus in Animal Groups." Science, 2011; 334 (6062): 1578 There has also been increasing attention to who doesn't vote and why. See, e.g. this Pew Study. This has been in the context of a growing political narrative of a view on the right that "cheating" and violating long standing political process norms is justified to prevent newcomers and outsiders who are inferior to them from gaining political power and harming them as they become a minority. The abandonment of the assumption of perfect rationality has also spurred whole sub-disciplines outside political theory such as behavioral economics.
• While not strictly limited to the last twenty years, political theorists have noted with increasing interest the surge of Americans (mostly younger) who identify as not religious, which happened half a century later than it did in much of Western Europe, what that identification really means politically and otherwise, and why it is happening now. The rise of the "nones" has been found to have significant political consequences. One aspect of this has been recognition of the "secular left" or "non-Christian left" as an increasingly dominant faction among white, Anglo Democrats. See, e.g., Pew Research Center, "In U.S., Decline of Christianity Continues At Rapid Pace" (October 17, 2019).
• The problems with single member district plurality voting systems, including gerrymandering and spoiler effects, which were widely recognized in the post-WWII wave of constitution making in Europe, have caught the attention of scholars and policy makers in the U.S. resulting in the adoption of ranked choice voting in Maine, and the establishment of the requirement that candidates who do not receive majorities face runoff elections in jurisdictions beyond Louisiana where this was long standing. Similar concerns have also motivated efforts to mandate open primaries in many states and an all party primary system in California. It has also spurred the national popular vote movement in Presidential races. Novel methods of quantifying and defining gerrymandering have been developed in the last twenty years. See Nicholas Stephanopoulos and Eric McGhee, "The Measure of a Metric: The Debate Over Quantifying Partisan Gerrymandering", Stanford Law Review, Forthcoming (November 30, 2017). There has also been significant experimentation with alternative voting procedures that reflect differences in intensity of preferences between voters in other contexts, for example, in budget decision making in the Colorado legislature, and in decisions on renaming of subdivision originally named after a KKK leader in Denver. In part, this interest has been driven by an unprecedented string of candidates who have won the popular vote but lost the electoral vote in U.S. Presidential elections. As one tech industry figure put the matter, there is a perception that "The United States had become “the Microsoft of nations”: outdated and obsolescent." Stanford University lecturer and entrepreneur named Balaji S. Srinivasan (2013).
• Our understanding of the process by which the political coalitions that make up the two major political parties are constantly tweaked and evolve has been greatly refined. See, e.g., “The Coalition Merchants” (2012) by Hans Noel. There has also been increased recognition that the national Democratic Party and Republican Party coalitions are not simply mirror images of each other. See Peter Ondish, Chadly Stern, "Liberals Possess More National Consensus on Political Attitudes in the United States: An Examination Across 40 Years" Social, Psychological and Personality Science (September 14, 2017). Some in this field, in response to arguments that socio-economic elites in the 1% control everything and are cohesive in doing so note, as this political scientist did that: "Movements like WTF embrace the pernicious myth of populism that beneath elite squabbles there exists widespread unity of principles." Julia Azari at Mischiefs of Faction (July 12, 2017).
• The YIMBY (yes in my backyard) has developed in response to the perceived macro-level downsides to allowing everyone to take a NIMBY (not in my backyard) attitude towards various kinds of land uses like high density housing, permitting sex offenders to live in any area, etc. This attempts to identify governmental and non-governmental regulations that stand in the way of desirable ends. See, e.g. Generation Priced Out (2018) by Randy Shaw.