Likewise, in tort law (mostly personal injury cases), the vast majority of lawyers are either "trial lawyers" who represent people who were harmed in accidents, or "defense lawyers" who represent people who are sued for causing harm. I've worked on both sides of tort law, although not at the same time.
Similarly, in cases involving consumer transactions, the vast majority of lawyers who handle the cases either represent consumers, or represent people suing consumers. Most bankruptcy lawyers, in the same vein, either help people file for bankruptcy, or represent creditors in bankruptcy.
The law doesn't require that lawyers take sides, but it is a useful approach from a business development perspective and also makes it much less likely for conflicts of interest to arise in the lawyers practice, something that is legally regulated.
Tax lawyers in private practice represent taxpayers, while tax lawyers in government service typically represent the government as it tries to collect taxes and administer the tax system (a few anomalies arise when state and local governments seek to enter into tax sensitive transactions with non-governmental parties, for example, when I represented a special district to advise it on its withholding taxation options).
There are exceptions. While some family law lawyers typically represent husbands, or typically represent wives, the norm is to represent both routinely. Likewise, there is not a strong plaintiff or defendant orientation in business to business commercial litigation. But, the exceptions make up a fairly modest share of lawyers who routinely engage in litigation.
Often business development considerations align specialties in particular types of law more broadly. A firm typically represents either big businesses or individuals, not both (with the exception of some non-conflicting provision of the legal needs of management). The division may be even more fine. It isn't unusual for a firm that is involved in construction law to represent primarily general contractors, primarily subcontractors, or primarily property owners. White collar criminal defense lawyers often practice in different firms than lawyers for individuals accused of "blue collar" criminal offense, but often practice in the same firms as lawyers who handle professional licensing matters.
As repeat players who clients have similar interests in every case, lawyers with this kind of specialization become not just advocates for clients in particular cases, but also advocates for interpretations of, and changes in, the law that favor their clients in their particular specialty. This is one reason that lawyers make up such a large share of lobbyists.
A particularly frank discussion of an area of law from this strategic point of view can be found at the Drug and Device Law Blog which is operated by two product liability lawyers who represent companies sued in product liability suits. Many of their clients will be sued only once or twice in the careers of the managers in place at that company. But, as litigators, they have an interest in taking the long view about what is or is not in the interests of their class of clients and developing a combined litigation, advocacy and legislative strategy that promotes those interests over, in their case, a quarter of a century. Their blog, which is well done despite its clear bias (most political and legal blogs have some sort of bias), is part of that overall advocacy effort.
Their post opens up noting:
The two of us have been practicing law now for a little over 25 years. Bexis graduated law school in 1982 and Herrmann a year later (see our bios - links at the top - for the gory details). At big firms it takes a few years – five at least – before we could start to have any real strategic impact on the cases we were working on. And it took a few years for us to get around to being product liability defense lawyers in the first place.
But now we’re here, there, whatever.
We’ve been doing product liability defense for the better part of a couple of decades, and we’ve got maybe a couple of decades more to go. So how are we – not just us, but this generation of the defense bar generally – doing at this midpoint of our careers?
Bottom line: Are our clients better off now than when we started?
Making a class of clients better off now than when you started isn't part of the job description for an attorney, thankfully, because the results are frequently beyond your control. But, a great many lawyers assume the responsibility anyway, and civic involvement to reform the legal system is specifically permitted by the rules of ethics for lawyers. Indeed, the ability of lawyers to participate in law reform is one of the important distinctions between "rule of law" states, and "rule by law" states, that take the mostly vestigial British tendency to speak of the "loyal opposition" and to view lawyers as "officers of the court" much more seriously than is the case in U.S. practice.
The ethical concern is professional independence. While on one hand, lawyers are zealous advocates for their clients (a word that has left the actual text of the ethical rules in many states), who are expected to take the side of their clients even when they know their clients are in some way in the wrong, lawyers are also supposed to exercise their independent professional judgment in cases. There is a potential (I don't accuse this blog's authors of having crossed the line despite their language that seems to imply that notion) to forget that the lawsuits are between your clients and their clients, not between you and the opposing counsel.
Indeed, one of the important lessons I learned from mentors while I have practiced law is the rhetorical usefulness of clearly distinguishing between you the lawyer, and the client you represent, in correspondence with opposing counsel and third parties. It keeps the discussion civil and makes it easier to engage in the passive-aggressive, tennis-like game called civil litigation.
The notion that the polity is full of special interests contending for political power is nothing new. The Founders were well aware of it when discussing the proposed constitution of 1789 in the Federalist Papers, discussions still widely read by political science students and law students today. But, nothing magical weds this kind of strategic advocacy to the legal profession. British barristers and advocates within the French Council of State are deliberately assigned cases in a way that puts them on both sides of litigation. A barrister may represent the prosecution one day and the defense another. The Council of State assigned lawyers working for it to defend the government from a complaint one day, and to represent a member of the public who has filed a complaint the next. My understanding, although it is very limited (based upon personal contacts with Japanese lawyers in law school many years ago) is that Japanese lawyers take a similar approach.
Part of the ability of advocates in those systems to take both sides is that somebody else is typically doing the grunt work. Stereotypically, a solicitor (non-trial lawyer) in the U.K. presents a case to a barrister, literally tied with a ribbon, containing all the preparation work that needs to be done in a case which the barrister will then present to a court. In criminal cases, non-lawyer members of law enforcement typically do all or almost all of the evidence gathering before the case is deemed ready to turn over to a prosecutor. Also, in criminal cases, it is common for a public defender, in a case that goes to trial, to test and question the sufficiency of the evidence presented by the prosecution, while offering relatively few defense witnesses or evidence to contradict prosecution claims.
In contrast, in U.S. law, it is typically for a client to have a "regular lawyer" who helps a client organize its affairs with the potential of litigation in mind, counsel the client as the events giving rise to litigation unfold, actively participates in the development of evidence and disclosure of evidence to opposing parties, conducts motion practice, and then represents the client at trial, and often, on appeal as well, if necessary. This is obviously not the work of a single lawyer in the case of a larger enterprise, but there is often a single or primary law firm for the company, and a single lawyer at that firm who coordinates the work and serves as the primary point of contact with the client.
When litigation is as vertically integrated as it is in the United States, it is harder for litigation attorneys to jump easily from one client to another with conflicting interests. Lawyers are more invested in, and more closely identified with, their clients than in many countries, despite the fact that formally, representation of a client does not directly imply that one identifies with one's client.
The full service legal practice orientation is also one of the reasons that law does not make as much of a formal distinction between its "rainmakers" and service providers as many industries, despite the fact that it talks about the distinction a lot and gives the distinction considerable importance in compensation arrangements. Maintaining that relationship over time, which is quintessentially legal counsel work, is typically the job off the "rainmaker" who brought the client to the firm, even if much of the detail work is delegated to others. Clients have a right, protected by legal ethics, to terminate a lawyer at any time without cause, and must be wooed one day at a time, not once and for all.