As you may have heard, Ted Cruz of Texas is currently engaged in a primary run-off with Republican opponent David Dewhurst, with the vote to be held July 31. Today Cruz’s campaign announced in a fundraising e-mail that an internal poll shows him leading Dewhurst 49 points to 40, with especially strong leads among “very conservative” and “Tea Party” voters. (Cruz won 34 percent of the vote in the original primary election, to Dewhurst’s 44.)