A few of the potential challengers are mulling repeat bids after losing in 2014, betting that growing voter discontent with incumbents will put them over the top in two years. Many of the primary campaigns are almost certain to fizzle once the reality of what it takes to dethrone a sitting lawmaker sets in. Regardless, it’s a rude awakening for a Republican establishment that hoped it had put insurgent challenges to rest.

“There is an unprecedented level of disquiet,” said Daniel Horowitz, who has worked as a political strategist for tea party groups. “There’s a sense that the Republicans in Washington don’t share the beliefs of the conservative platform, or don’t fight for them.”

Democrats have comparatively fewer divisions, despite being in the minority in both chambers of Congress. In party circles, there’s little talk about primaries.

The most serious potential Republican primary race is in North Carolina, where Ellmers has come under ferocious criticism on an issue of central importance to conservatives: abortion. Jim Duncan, chairman of the Chatham County Republican Party, is said to be considering challenging Ellmers following her successful push to stop the passage of an anti-abortion bill that she criticized as too stringent. It required a rape victim to report an assault to authorities in order to qualify for an exemption from the bill’s restrictions on abortion after 20 weeks of pregnancy.