Realignment Likely To Continue

A Democrat, Lamb, won the 18th Congressional District that went to Trump by almost 20 percentage points in 2016 by a fraction of a percent in a special election held yesterday. Using the Cook's political report R+11 partisan voting index of PA-18 as a benchmark, only 112 Republican seats in Congress are safe seats. The other 126 GOP seats in Congress are vulnerable.

Control changes in the U.S. House of Representatives if the Democrats pick up 24 seats. This is possible winning only seats that are R+2. Just ousting Republicans from districts where Clinton got more votes than Trump would flip 23 seats in Congress.

In the Senate, the Democrats have lots of incumbents in conservative states defending races but if it can hold them, only needs to pick up two seats with Arizona and Nevada looking particularly promising.

Court ordered redistricting in Pennsylvania could flip four more seats to Democrats. Special elections since 2016 have favored Democrats by eight percentage points relative to what would be expected based upon PVI only.

The House has become well-sorted out: only 35 of 435 districts "crossed over" to vote for presidential and House candidates of opposite parties, down from 108 in 1996. Today, there are 23 Republicans sitting in districts Clinton carried, and 12 Democrats sitting in districts Trump carried. However, this is slightly higher than the record low of 26 "crossover districts" following the 2012 election.

From Cook's Political Report.

Given prevailing political trends a lot of those 23 "Clinton Republican" seats are going to swing to the Democrats.

Less obvious is how that breaks down regionally. 

Seven are in California. One is in Washington State. Two are in Pennsylvania. One is in New York State. One is in New Jersey. One is in Illinois. One is in Minnesota. One is in suburban Denver.  One is in Virginia in suburban DC. Two are in the far southern tip of Florida. One is on the Rio Grande border with Mexico in Texas, another from Texas is in Austin, and a third in Texas is from suburban Houston. One is in Arizona. One is in Kansas.

In other words, most of these district are on the tail end of the long process of "realignment". Pacific Coast Republicans and Republicans in the Northeast are continuing to become an endangered species. Blue enclaves in red or purple states are poised to oust Republican members of Congress. 

The Republican party has become a Southern/Rural White Christian nationalist party.