One trend that's been pretty hard to miss in the past few presidential cycles is the increased number of Republicans running for the job. This year has seen a very crowded field, while the Democratic contest has been relatively small and not very competitive.
It turns out that this trend isn't limited to the presidential level and can't just be explained by the rise of a few big personalities in recent races. The same thing is going on at the congressional level, as well. I looked at Federal Election Commission data to see how many congressional candidates had filed to run by party. The data is only available from 2008 on, but it tells an interesting story:
In 2008, there were essentially equal numbers of Democrats and Republicans who ran for Congress — roughly 1,000 each. In 2010, the year of the Tea Party insurgency, the story was very different, with nearly 1,700 Republicans filing but only about 950 Democrats doing so. The number of filings for both parties has dropped since 2010 (although we're still relatively early in the 2016 cycle), but Republicans have maintained a substantial advantage in numbers of candidates.
Included in these numbers, no doubt, are a number of flaky candidates who never really got their campaigns together. But I ran the same analysis just limiting it to candidates who had recorded actual donations, and it's the same basic pattern.
Having a lot of candidates can be helpful, giving party insiders and primary voters a good range of people to choose from. But it can also create a coordination problem. Party insiders like to steer primary voters toward a candidate who will advance party goals but also be electable in a general election. They do so by endorsing such candidates and otherwise channeling campaign resources toward them. This can be effective in a relatively small field. With lots of candidates it gets harder, and the odds of a well-known, wealthy candidate winning, even if he or she is not the insiders' favorite, goes up.
It's not entirely clear what's causing this discrepancy between the parties. Julia Azari and I wrote yesterday about the relative over-recruitment and undercoordination on display in the GOP right now. What's going on at the presidential level — a surplus of candidates that makes it difficult for the party to pick a favorite — seems to be occurring at the congressional level, as well.
I hesitate to use the word "recruitment" here; many Republican Party leaders probably do not want all these people running for office. Yes, it's good to have an enthusiastic pool of candidates, but it's also risky, inviting chaotic outcomes like the defeat of a dependable incumbent. (Just ask Eric Cantor.)
What's more, all these candidates are likely contributing to party polarization on the Republican side, and are part of the reason we've seen asymmetric polarization in recent years. Many of these candidates are running to challenge long-standing party incumbents. Either those incumbents survive by tacking right, or they lose to someone who's already more extreme than they are. With fewer candidates running on the Democratic side, there's just not as much pressure to tack left in that party.
To be sure, not every challenge is from the fringes, and to say over-recruiting is the cause of polarization is just to invite the question of where the over-recruiting comes from. But it doesn't seem a real stretch to say that the Republicans right now have more candidates than they know what to do with.