Here's how the new Democratic members of the House sort out ideologically
If you have any familiarity with the Harry Potter series, you probably know that one of the first things that happens to you upon arriving at Hogwarts is that the Sorting Hat tells you what house you’re going to belong to. That’s a really important decision, because it tells you who your friends are going to be, what kind of adventures you’re going to go on, and basically whether you’re going to be one of the story’s heroes, villains, or anonymous supporting characters.
Well, there’s something similar afoot in the House of Representatives; the Democratic members tend to self-sort into three different ideological caucuses: the Congressional Progressive Caucus (who represent the left flank among House Democrats), the New Democrat Coalition (who represent the generic middle of the party, or the center-left on the broader political spectrum—they’re sort of the Hufflepuffs of the House Democrats), and the Blue Dog Coalition (the centrists who represent the party’s right flank, though their numbers are significantly reduced since their pre-2010 heyday). The Republicans, in fact, now have something of a mirror-image setup, with three caucuses—the Main Street Partnership, the Republican Study Committee, and the Freedom Caucus—representing their center-right, establishment-right, and hard-right.
Obviously the Harry Potter metaphor falls apart a bit here, because, for starters, there are only three caucuses instead of four (and one of the three has already had most of its hapless members struck down by Death Eaters). In addition, you can freely select which one you belong to, and you can also opt to belong to more than one of them. You also, of course, have the option of not belonging to any of them, and dozens of members take that approach.
And beyond that, caucus membership doesn’t compel you to vote a particular way on a particular issue; nobody gets kicked out for being heterodox, and there in fact are a handful of Progressive Caucus members whose overall voting records put them to the right of the House Democratic caucus’s midpoint (and even one Blue Dog—Mike Thompson—who’s to the left of the caucus’s midpoint). It’s really just more who your friends are and who has your back in intramural quidditch matches, even while it’s generally predictive of your overall voting record.
So, with a huge number of new Democratic arrivals in the House this year, we thought we’d take a closer look at how they all sort out, which can give us at least some clue about how the various new members will behave in the coming years. The above graphic shows where they land; the Venn diagram format is especially appropriate here, because many members are “double-dippers” who have joined two caucuses, and showing the tweeners adds some nuance to where they’re likely to fall in the Democratic spectrum. We’ve also created a Google doc showing the same information in a columnar format that may be easier to read.