SAN ANTONIO (AP) The question for voters in Tuesday's Texas runoff isn't whether a Republican will likely succeed Kay Bailey Hutchison in the U.S. Senate, but what kind of Republican? The answer figures to reverberate far beyond the Lone Star State.

In an election representing one of the nation's most vivid contrasts between the GOP establishment and the tea party, longtime Lt. Gov. David Dewhurst faces a major threat from former Texas Solicitor General Ted Cruz. Two months after Dewhurst's decisive win in a nine-candidate primary signaled he might coast to victory, the battle is considered too close to call.

Cruz blocked Dewhurst from the majority he needed to avert a runoff, and his insurgent candidacy has been buoyed ever since by money and influence from conservative groups in and outside of Texas.

Both camps pinned their hopes on getting people to the polls for Tuesday's runoff, which was pushed to summer because the initial primary was delayed from Super Tuesday to May due to a legal battle over redistricting maps drawn by the GOP-dominated Legislature.

"We are seeing a high turnout, which I think is terrific because everything we're seeing is that conservatives are energized and excited and showing up to vote," Cruz said Monday on the Joe Pags Show on WOAI radio in San Antonio. "This race will come down 100 percent to turnout."

At a Houston campaign stop early Tuesday, Cruz once again emphasized the need for "conservatives" to vote, telling them not only to cast their own ballot, but to bring 10 friends with them.

"We are here today because of grass-roots conservatives all over the place," Cruz told about two dozen supporters who stood outside a polling place in one of Houston's most upscale neighborhoods.

Cruz said he heard from voters statewide interested in changing what they view as insider-politics in Washington.

"That's the way the Democratic process is supposed to work. It's not supposed to be a bunch of guys in a smoky room in Austin picking the next Senator," Cruz added.

Dewhurst also planned to meet voters in Houston.

Early voting ended Friday, and about 3.3 percent of registered Republicans cast ballots a stronger turnout than expected, especially for a runoff coming so deep into summer doldrums.

Natache Reeves, a 42-year-old nurse from the Dallas-Fort Worth suburb of Grapevine, said she voted for Cruz because he had former Alaska Gov. Sarah Palin's support and was less likely to restrict handgun use.

"I love Sarah Palin, and she's backing Ted Cruz," Reeves said. "I pretty much agree with everything that rolls out of her mouth."

Frank Martinez of Dallas said he couldn't support Cruz even though they shared Cuban roots, and despite finding Dewhurst's campaign ads "very mean."

"I think (Dewhurst) has more experience, and he's not a lawyer. So the ad worked," said Martinez, a 54-year-old immigrant who is unemployed after a workplace accident two years ago left him disabled.

The race is being watched nationally as a test for the tea party against well-entrenched Texas Republicans who unaccustomed to losing. Texas hasn't elected a Democrat to statewide office since 1994.

Cruz's recent success is drawing comparisons to Indiana, where state Treasurer Richard Mourdock defeated incumbent Sen. Richard Lugar in the Republican primary. But in Texas, the nation's second-most populous state, a win by a tea party-backed candidate likely would resonate even more.

While Democrats also are squaring off in a Tuesday runoff, the GOP nominee figures to be the overwhelming favorite in November to replace Hutchison, who is retiring.

Dewhurst has overseen the Texas Senate from the powerful lieutenant governor's post since 2003 and has been endorsed by popular Gov. Rick Perry and much of the state's Republican establishment.

Cruz is the son of a Cuban immigrant who has a fiery public speaking style that has stirred up grassroots groups.

An Air Force veteran who also was stationed in Bolivia for the CIA, Dewhurst spoke Monday in San Antonio at one of the oldest Veterans of Foreign Wars posts in the country, flanked by Perry and Peter Holt, the owner of the city's NBA franchise, the Spurs.

Retired U.S. Navy fighter pilot Jake Ellzey spoke at the rally, telling the crowd, "I dare Ted Cruz to come in to any VFW post anywhere in the state and talk about fighting."

"Mr. Cruz, you're not a fighter because you've never worn the uniform," Ellzey said.

Asked if that was a fair assessment, Dewhurst said, "I agree with the commander."

"Normally, I've found in my life that the louder you speak, probably, the less of a fighter you are," he continued.

Cruz describes himself as the race's only true fighter for conservative values. A spokesman for his campaign, James Bernsen, said Monday that Ellzey's and Dewhurst's comments offended him as a veteran of the Iraq war.

"I find it offensive to make it a litmus test," Bernsen said. "Ted is very supportive of the military. But this is not something that should be politicized, period."