An early test of Kevin McCarthy‘s potential speakership is looming outside Houston, where he and some of the GOP’s biggest provocateurs have lined up on opposite sides of a primary that will shape the temperament of the next Republican House majority.

A group of MAGA firebrands, including freshman Reps. Madison Cawthorn (R-N.C.) and Marjorie Taylor Greene (R-Ga.), are catapulting into a GOP primary here to boost Christian Collins, a far-right activist who has vowed to govern in their image.

But they are facing fierce resistance from other powerful GOP figures, including McCarthy, who have aligned behind a different candidate, former Navy SEAL Morgan Luttrell.

This March primary for a deep-red seat pits MAGA forces against the Republican establishment, and the skirmish is part of a larger fight to determine the contours of a possible new GOP majority. McCarthy’s involvement suggests that this year, he won’t shy away from intervening in deep-red primaries if the outcome could determine whether he leads a majority that is largely aligned with his goals — or one with a significant faction of rabble-rousers willing to publicly stymie his plans.