WASHINGTON – The fight is on for the hearts and minds of Texas conservatives, whose affections could decide the Republican primary for governor. Many remain skeptical about Sen. Kay Bailey Hutchison.

"It's going to be the issue: Who is more conservative?" said Cathie Adams, who represents Texas Republicans on the party's national committee. "The more conservative is going to win, because that's the way Texans think."

Backers of Gov. Rick Perry make no bones about their view that Hutchison is not just less conservative – she may not qualify as a conservative in the first place. But even a cursory glance at years of interest-group scorecards makes it hard to argue she's only a moderate.

Based on her votes, she has near-perfect scores from anti-tax groups and the gun-rights lobby, and an 89.4 lifetime rating from the American Conservative Union. NARAL Pro-Choice America, which advocates abortion rights, has given her a zero the past four years, the same score she gets from gay-rights advocates.

The nonpartisan National Journal ranks her the 20th-most conservative senator, in the middle of the GOP pack.

Yet the perception persists that she is something less than a rock-solid conservative. It's a vulnerability Hutchison is eager to overcome as she prepares to take on the governor, and she would love to reframe the issue as one of style rather than substance.

"Because I speak in civil tones, some want to try to label me a moderate," she said. "My voting record is one of the most conservative in the U.S. Senate. ... We can't expect to remain the majority party in Texas if we drive out voters that support Republican principles but might not agree on every single issue."

Yet for many conservative voters, there are litmus tests.

Some anti-abortion-rights activists can't forgive the senator for her belief that abortion should remain legal with some limits – no matter how often she votes with them to curtail funding and availability. Last year alone, she voted to let states make fetuses eligible for health-care coverage and to make it a crime for anyone besides a parent to accompany a minor to an out-of-state abortion provider.

"Overall, she's very conservative," said John Gizzi, political editor at Human Events, a conservative magazine. "But she is pro-choice. She would never overturn Roe v. Wade."

He identified another factor that has fueled mistrust: In 1976, the senator and her husband backed President Gerald Ford against challenger and future GOP hero Ronald Reagan. Primary voters punished Ray Hutchison two years later when he lost a run for governor.

"The Texas breed of elephant has a long memory," Gizzi said. "She has never been able to shake that off."

Perry throws his weight behind red-meat ideas such as requiring sonograms for women seeking abortions, as he did during the recent legislative session. Hutchison typically focuses on more everyday issues, like trying to prolong a $30 million Justice Department grant program that helps local police enforce drug laws.

There are all sorts of conservative causes, though, and she has shined in some areas.

When it comes to the Second Amendment rights, Hutchison hasn't merely voted against efforts to limit gun owners' rights. She championed a drive to overturn the nation's most restrictive gun laws, in the District of Columbia.

"It's easy for people to sit on the sidelines," said Andrew Arulanandam, director of public affairs at the NRA, which gives Hutchison its highest marks.

The assessment is mirrored at the Brady Center to Prevent Gun Violence. Meetings with Hutchison aides are invariably cordial, said spokesman Peter Hamm, but "for what it's worth to the conservatives in Texas, she's never voted with us."

On immigration, Hutchison repeatedly has voted to allow more guest workers; she also helped block the 2007 McCain-Kennedy bill, viewed on the right as amnesty for lawbreakers. She has pushed for more border agents and supported a fence along the U.S.-Mexico border; she also voted to limit funding for that project.

"I don't know why she wants to gut the fence, because she likes to play both sides of it," said Bob Dane at the Federation for American Immigration Reform, which seeks tighter controls on immigration. "If you were looking for a letter grade, I'd give her an S for squishy."

Defenders say complaints stem mainly from her aversion to confrontation and inflammatory rhetoric, not from rejection of party orthodoxy.

She's outspoken on national security and the so-called marriage penalty in the tax code. But when it comes to causes that electrify the grassroots, though, she's more likely to follow the pack than to lead it.

"Her tax votes have been good," said Grover Norquist, president of Americans for Tax Reform, which gives Hutchison a 95 rating. "The interesting question is, does the perception [that she's not a solid conservative] ... come from demeanor, because she's not out front" on social issues?

That difference – between voting record and advocacy – may account for her solid 87 score from Eagle Forum, the group founded by Phyllis Schlafly – and for the fact that Texas Eagle Forum's president, Adams, is poised to announce an endorsement of Perry.

Perry is "definitely a conservative," Adams said, emphasizing the "definitely" in a way that suggests she can't say the same of Hutchison.

"On national defense, she has been stellar," Adams said of the senator. "On some issues, yes. And on other issues, not. ... One of the things we know about Rick Perry is that he is unafraid of controversy."

To be sure, there are diehard conservatives in both camps.

Denise McNamara, the previous RNC committeewoman from Texas, called Hutchison a "sincere statesman" and "absolutely" a conservative. She faults the governor for trying to require Gardasil vaccines for preteen girls and for endorsing an abortion-rights supporter, former New York Mayor Rudy Giuliani, for president.

Another Hutchison backer, Edd Hendee, the radio host and Houston restaurateur, also defended the senator's bona fides.

"I'm a very strong conservative. ... I can't identify with somebody that runs counter to my principals," he said. "I'm happy to support her."

He said it's no accident that since winning statewide office, Hutchison has never faced an opponent from the right – until now.