The Senate’s second-ranking republican—Texas Senator John Corny– now has a fellow GOP challenger. Republican Congressman Steve Stockman is launching a GOP primary challenge against Cornyn, who is up for re-election next year.

Stockman is a Tea Party favorite. He says he decided to mount the primary challenge in part because he says Cornyn “undermined” Ted Cruz’s fight to derail the Affordable Care Act.

The primary is March 4. Stockman was elected to the house last year, Cornyn was elected to his second term in the Senate in 2008.