Few people thought Rep. Steve Stockman would pose a serious challenge to Sen. John Cornyn in a Texas Republican primary race early last month.

Stockman, after all, was perhaps best known in Congress for his occasional outlandish statements, such as, "If babies had guns, they wouldn't be aborted." And in the lead-up to the primary election, he was nowhere to be seen, at one point even disappearing without explanation for a three-week stretch.

But Cornyn wasn't messing around. His campaign spent an eye-popping $5.47 million from January through March to ensure Stockman wouldn't stand a chance.

That leaves the campaign with a cool $3.35 million, in addition to whatever money Cornyn raises during the next seven months, for a general election contest in which Cornyn is the prohibitive favorite to win.

“We are proud of our steady, strong support from across Texas, and the campaign will have no shortage of resources as Sen. Cornyn works to unite our coalition and expand the party heading into November," said Cornyn's campaign manager, Brendan Steinhauser.

For months leading up to the Republican primary, Cornyn's team worked tirelessly to build up a campaign war chest that would ward off primary challenges from Tea Party insurgents. As the filing deadline approached in December, it appeared Cornyn had done just that.

Then, Stockman announced that he would run, citing Cornyn's insufficient support for Sen. Ted Cruz, R-Texas, preceding the October government shutdown. Cornyn, the Senate minority whip, had opposed shutting down the government to fight funding for Obamacare.

But Stockman's Senate bid, if it could be called that, was perplexing at best. He skipped House votes for three weeks in January, absences that his staff refused to explain to reporters. He framed himself as a Tea Party insurgent in the vein of Cruz, who won an unlikely Republican primary bid in 2012, but Stockman had not voted in a party primary since 2004. And he hardly campaigned at all.

Cornyn won the primary race handily. And, apparently, wasn't afraid to spend a bit to do so.