Texas Runoff Between Cruz and Dewhurst Fiercely Contested FORT WORTH - At the opening ceremony of the Texas Republican Party's convention here - typically a time for delegates to show unity for their party and principles - thousands of conservatives cheered and rose from their seats as Gov. Rick Perry took the stage on Thursday. But a few minutes into his speech at a downtown arena, many in the crowd nearly drowned him out with boos. The reaction had nothing to do with the governor's role as a former presidential candidate, but everything to do with his support for a fellow Republican, Lt. Gov. David Dewhurst, who is locked in a fierce race with a former Texas solicitor general, Ted Cruz, to determine the Republican nominee for the state's open United States Senate seat. "We need more strong conservatives in Texas, and we need more conservative Texans in Washington, D.C., including my friend David Dewhurst," Mr. Perry said, ignoring the boos that erupted when he uttered Mr. Dewhurst's name. The race to succeed Senator Kay Bailey Hutchison, who is retiring, has transformed Republican politics in the state, pitting Tea Party-backed activists against the Texas power structure, which is led by longtime incumbents like Mr. Perry and Mr. Dewhurst, both of whom have taken stands that have riled grass-roots Republicans and opened them to criticism that they have not been conservative enough on some issues. Intraparty disputes are not new among the conservative camps in Texas, but rarely have the divisions become as heated as they have between supporters of Mr. Dewhurst and Mr. Cruz. Tea Party activists and their grass-roots colleagues have grown frustrated by what they see as the eagerness of the establishment to compromise with Democrats and to shy away from a bold conservative approach. Many of Mr. Cruz's backers say that Mr. Dewhurst is the reason two bills they support stalled in the Legislature last year: a Tea Party-backed measure that would outlaw "intrusive" pat-downs at airport security checkpoints, and legislation to penalize so-called sanctuary cities like Austin and Houston that prohibit the police from inquiring about the immigration status of those they arrest or detain. It is a battle that has played out in Senate races around the country, in which establishment Republicans have lost to Tea Party-supported challengers. They include the defeat this year of Senator Richard G. Lugar of Indiana to Richard E. Mourdock and Senator Robert F. Bennett of Utah to Mike Lee, and the loss of Gov. Charlie Crist of Florida to Marco Rubio, a Cuban-American Tea Party star, in the 2010 Senate race. Mr. Cruz, who is also Cuban-American, is often compared to Mr. Rubio. "Ted taps into the energy on the right," said Matt Mackowiak, a Republican political consultant and former Hutchison spokesman who supports Mr. Cruz. It's a similar dynamic to what you've seen in some of these other states, where an established statewide elected official is somewhat conservative but not boldly conservative. In the current environment, that's what Republican primary voters want. The day after Mr. Perry's speech, Mr. Dewhurst took the stage to address convention delegates. There were scattered boos and chants of "Cruz" at the beginning of Mr. Dewhurst's remarks, but for the most part, Mr. Cruz's supporters remained silent. For Mr. Perry, the outburst the day before was a stunning moment, unlike anything he had faced in office - a Republican governor of a solidly Republican state being booed at a Republican convention for declaring his support for an influential Republican lieutenant governor. "It shows that Perry is out of touch with the grass roots," said Konni Burton of Colleyville, a Cruz supporter who is the vice president of the Northeast Tarrant Tea Party in the Dallas-Fort Worth area. You get in a bubble, and I think that's where they are right now frankly. Mr. Dewhurst and his supporters played down the audience's reaction, saying it did not reflect the hundreds of thousands of Texans who will cast their vote in the July 31 runoff. Standing outside a campaign booth at the Fort Worth Convention Center shortly after his speech, Mr. Dewhurst wondered if some of those booing were frustrated supporters of Representative Ron Paul of Texas, the Republican presidential candidate. "I don't see any division within the Republican Party," Mr. Dewhurst said. We're united in our conservative principles and our goals. The tug back and forth between different groups that are supporting one candidate over another is normal in the political process. It doesn't surprise me at all. Mr. Cruz and his campaign have tried to frame the race as a David-and-Goliath battle, and in many ways, it is precisely that - a lawyer who has never held elected office has forced one of the wealthiest and most powerful elected officials in Texas into a runoff by placing second in the Republican primary in late May. Paul Sadler, a former state representative, and Grady Yarbrough, a retired educator, are in a runoff for the Democratic nomination, but no Democrat has been elected statewide since 1994. Mr. Cruz was outspent by Mr. Dewhurst - both campaigns have raised more than $6.1 million, but Mr. Dewhurst, a rancher and businessman, has pumped an additional $10 million of his personal fortune into his campaign. The average contribution to Mr. Cruz was $167, compared with $1,653 to Mr. Dewhurst, a figure supplied by the Cruz campaign to highlight his connection with grass-roots conservatives. In the primary, Mr. Cruz won 34 percent of the vote. Mr. Dewhurst, at 44 percent, was well short of the 50 percent needed to avoid a runoff.