National Tea Party groups went all-in for Midland University President Ben Sasse in the a four-way Senate primary to succeed retiring Sen. Mike Johanns (R ). Tuesday’s outcome won’t affect control of the seat, but will be an important test of those groups’ credibility in a GOP primary.

The Nebraska race is the night’s main event to watch for hints of how much firepower the Tea Party has left this cycle. Conservative activists have also spent heavily in an open House seat in West Virginia that’s up for grabs.

Sasse emerged over a month ago as the frontrunner over former state Treasurer Shane Osborn thanks to conservative support and endorsements from Tea Party stars like former Alaska Gov. Sarah Palin and Sen. Ted Cruz (R-Texas). Sasse has been backed by the Senate Conservatives Fund, Club for Growth and the Madison Project, among others.

Still, Sasse’s nomination is not guaranteed. Over the past two weeks, banker Sid Dinsdale, formerly a long-shot third-place candidate, has surged as a result of the bitter spat between Sasse and Osborn. Dinsdale picked up the endorsement of the Omaha World-Herald and was second in an overnight internal poll out from Sasse’s campaign last week, 11 points behind Sasse.