How scared should House freshmen be of threats to primary them?

The stereotypical primary challenger is a young upstart facing a longtime incumbent, but I was curious how common it is for freshly minted incumbents to be ousted by a successful primary challenger after serving only one term. It turns out, it happens more often than I expected. Using Bloomberg reporter Greg Giroux’s database of members of Congress who were defeated for renomination, I found that nine freshman representatives have lost primary challenges since the 2000 election.1 Granted, that’s out of 626 total freshmen who served between 1999 and 2018,2 which means their rate of defeat was only 1.4 percent. That sounds low — and it is — but remember that it’s very rare for incumbents to lose primaries, period. Only 49 House incumbents of any tenure lost their primaries during this span, period — or, in other words, about 1.1 percent of all representatives. This means first-termers have historically been a bit more vulnerable, which makes some sense intuitively, as they are generally less established and haven’t had time to build the local relationships and fundraising networks that underpin a truly intimidating incumbency advantage.

But a closer look at the freshman incumbents who lost renomination suggests that Ocasio-Cortez, Omar and Tlaib (in addition to this session’s 82 other House freshmen) can probably rest a little easier: Unusual circumstances contributed to seven of the nine previous losses.