"While Congressman Stockman has a pro-economic growth record, so does Senator Cornyn, as witnessed by his 87% lifetime Club for Growth score," Club for Growth President Chris Chocola said in a statement. "Our PAC evaluates three factors when looking at races that involve incumbents: 1) the strength of the incumbent’s record; 2) the degree of difference between the incumbent and the challenger on economic issues; and 3) the viability of the challenger. None of those factors weigh against Senator Cornyn, so we do not expect to be involved in the Texas Senate race."
Interestingly, Club for Growth wasn't the only tea party group that responded cautiously to Stockman's announcement. The Senate Conservatives Fund, which endorses conservative challengers to Republican incumbents, did not immediately endorse Stockman. The group has repeatedly backed tea party challengers shortly after they announced their candidacies.
"We haven't decided yet whether we will endorse Steve Stockman, but we're glad he's running," Senate Conservatives Fund Executive Director Matt Hoskins said in a statement. "Texas deserves two conservative fighters in the Senate, not just one. John Cornyn has voted to increase the debt, raise taxes, bail out Wall Street banks, and fund Obamacare. He's part of the problem in Washington and voters deserve a choice."