This post has been corrected and updated. 

The anti-tax Club For Growth said Tuesday it doesn't plan to meddle in the Texas Republican Senate primary, even as Rep. Steve Stockman (R-Tex.) launched a surprise last-minute campaign against Senate Minority Whip John Cornyn (R-Tex.), who other tea party groups are eager to defeat.

“While Congressman Stockman has a pro-economic growth record, so does Senator Cornyn, as witnessed by his 87% lifetime Club for Growth score,” said Club for Growth President Chris Chocola 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."