Texas Republican Rep. Michael McCaul has loaned his 2010 re-election campaign $500,000, a reflection that his bid for a fourth term in the state’s 10th District will be an expensive campaign and possibly his most competitive.

According to an updated report that the congressman’s campaign filed with the Federal Election Commission ahead of a Thursday deadline, McCaul raised another $236,000 from individuals, political action committees and other sources in this year’s third quarter, for a total of $736,000 in overall receipts for the reporting period. He had $892,000 left to spend as October began.

McCaul’s likely Democratic opponent is Jack McDonald, a technology executive who is waging a well-funded campaign that is currently in what McDonald calls an “exploratory”
phase. McDonald reported raising $298,000 in the third quarter and $933,000 overall; he has $805,000 cash-on-hand. McDonald has loaned his campaign $26,000 in personal funds, including $25,000 in the third quarter.