As the Republican primary results poured in Tuesday evening, a general rule of thumb emerged in races featuring Tea Party insurgents challenging Republican incumbents: Money matters.

In the most closely watched races, strong interest among Tea Party activists in unseating an incumbent could not overcome a poorly financed challenger. The clearest examples were the victories of U.S. Sen. John Cornyn and U.S. Rep. Pete Sessions, of Dallas, both of whom were targeted by Tea Party groups. None of the challengers in the primary races raised enough money to overcome incumbents with deep campaign war chests.

Most of the clearest Tea Party victories Tuesday, such as Tony Tinderholt’s win over state Rep. Diane Patrick, R-Arlington, and Matt Rinaldi’s victory over state Rep. Bennett Ratliff, R-Coppell, were competitively financed.

In her bid to unseat Sessions, political consultant and activist Katrina Pierson drew the support of national conservative stars, including Sarah Palin, Michelle Malkin and Rafael Cruz, the father of U.S. Sen. Ted Cruz. But her campaign spent less than $200,000, while Sessions spent well over $1 million to hold on to his seat.

“We had a lot of support from people who knew me who had national name recognition, but we didn’t have the million-dollar checks,” Pierson said. “Given the fact that we didn’t have the millions of dollars and the name recognition, I think we put up a pretty good fight for a first-time challenger.”

Finding campaign funds was less of an issue in another Tea Party-infused Dallas race, Don Huffines‘ bid against state Sen. John Carona, who has been painted as a moderate by area conservative groups. The race emerged as one of the most expensive of the primary, as the candidates, both wealthy businessmen, invested heavily in a race that became dominated by mudslinging. In a nail-biter not decided until early Wednesday morning, Huffines defeated Carona by 635 votes.

Further north, John Ratcliffe, a former U.S. attorney and mayor of Heath, loaned his campaign $400,000 and outspent four other competitors to force longtime U.S. Rep. Ralph Hall into a runoff.

Cornyn’s seven-way primary fight drew strong attention largely a result of his fellow senator, Cruz, who has emerged as a kind of yardstick against which other Republican senators are measured by many Tea Party adherents. When Cruz and Cornyn differed on votes or tactics, politically influential groups like the Club for Growth excoriated Cornyn for his positions.

Activists viewed Cruz’s decision not to endorse Cornyn as a message to his supporters that Texas could do better.

“I think he made a statement without making a statement,” said Dwayne Stovall, who came in third in the primary.

Shortly before the campaign filing deadline in early December, U.S. Rep. Steve Stockman, R-Friendswood, launched a campaign for Cornyn’s seat that turned into something of a kamikaze mission. His hope that Tea Party groups and deep-pocketed conservative organizations would back his candidacy failed to materialize, in part because of lingering questions about his income and campaign finance practices that he largely refused to address.

As many Tea Party leaders began resigning themselves to sticking with Cornyn, Stovall began to pick up some momentum, a year after he began his upstart campaign. However, the support for Stovall came too late and was not broad enough to overcome Cornyn’s name identification and the more than $6 million he invested in his re-election.

While its failures draw more attention, the Tea Party movement in Texas became a victim of its own success in some instances. In many races, Republican candidates were fighting one another to claim the Tea Party mantle, with the result being activists splitting their support among the campaigns. Several Tea Party leaders said they were waiting for the May runoffs to get more invested in those races.