By Greg Giroux, CQ Staff

The surprise departure last week of a well-funded Democratic candidate in Texas’ 10th District has left Republican Rep. Michael McCaul in a sturdier political position as he campaigns for a fourth term.

CQ Politics has changed the rating of the Texas 10 race to Safe Republican as a result of technology executive Jack McDonald (D) announcing Dec. 22 that he would not pursue a campaign against McCaul that he had begun organizing 10 months ago.

The contest previously had been rated Likely Republican — a mildly competitive category that indicated that McCaul had a strong early edge but that there was the potential that a highly competitive contest could develop. With $933,000 in overall campaign receipts and $805,000 in cash-on-hand as of the end of September, McDonald was among the best-funded non-incumbent House candidates in the 2010 cycle. McCaul won his two re-election campaigns by solid but not overwhelming margins in a conservative-leaning district that includes strongly Republican-leaning suburbs of Houston and a Democratic-leaning piece of Austin.

Democrats now have no announced candidate against McCaul, who had been ramping up his own fundraising in the expectation he would face a serious challenger. And McCaul is running for re-election in a political environment that surely will be friendlier to Republicans than the pro-Democratic 2006 and 2008 campaign years.

CQ Politics will re-evaluate the rating of the Texas 10 race if there’s evidence that McCaul will face a competitive Democratic challenger. Prospective candidates must decide quickly: the Jan. 4 candidate filing deadline is just six days away.

To follow all of the 2010 House races, check out the CQ Politics ratings map.