Tomorrow is the Texas GOP primary — in the governor’s race, it’s a battle between incumbent Rick Perry and Sen. Kay Bailey Hutchison. Last fall, I wrote about the contest for NR.

Polls suggest that Perry will win. If he does, it creates an interesting conundrum for Hutchison. For months, she has promised to resign her Senate seat, win or lose — she made the pledge over and over, including in her interview with me. So far, however, she hasn’t quit. Assuming she doesn’t pull an upset, a lot of establishment Republicans will urge her to break her promise, on the grounds that the GOP doesn’t need the problem of having to defend a Senate seat that won’t be up until 2012. (It wouldn’t be her first broken vow: In 2006, she ran for a third term in the Senate, despite saying that she would serve no more than two terms.)

Yet conservatives may be happy to take a gamble in 2010, on the assumption that if Hutchison resigns, Perry would appoint someone like Michael Williams to replace her. It wouldn’t have the effect of switching a seat from D to R, but it arguably would nudge an R seat a little more rightward.