There is a line many conservative Republicans want Arnold Schwarzenegger (search), an actor-turned-politician, to recite with the same gusto as the "Terminator."

"I will not raise taxes ever. Period."

That is a paraphrase of something known in conservative circles as the "no-new-taxes pledge."

Vice President Bush took it in 1988 and won the presidency. He broke it in 1990 -- and lost in 1992. His son, George W. Bush, took it and won in 2000. He hasn't broken it.

Ninety percent of House Republicans have taken the pledge -- as have 80 percent of the Republicans in the Senate. One-third of the sitting GOP governors have also signed on.

The pledge has, for better or worse, become the litmus test for Schwarzenegger as he tries to woo conservative Republicans. The international film star and political novice has declined to take the pledge, he says, to maintain necessary flexibility in case he's elected and California is struck by a natural disaster or terrorist attack.

But the author of the pledge, Grover Norquist (search), told Fox News that's not good enough.

"Failure to sign the no-new-taxes pledge is the hole in the bottom of the Arnold Schwarzenegger boat," Norquist told Fox News. "Schwarzenegger is not Ronald Reagan. Without the pledge, he's not the anti-tax candidate."

In Norquist's estimation, the only remaining anti-tax candidate in the governor's race here is state Sen. Tom McClintock (search), who has taken the pledge and spent the better part of 20 years in the Legislature opposing tax increases. To maintain consistency, McClintock has even voted against state bonds to pay for low-income housing and education.

When Bill Simon (search) was in the race, there were two Republicans who had taken the pledge.

Now there's one: McClintock.

"For Arnold to win, he needs to take the pledge," Norquist told Fox News. "He has to establish his conservative bona fides. If he is to win, other Republican candidates have to defer. The only way they do that is if he takes the pledge."

But the line from this conservative script sticks in Schwarzenegger's throat.

"No, I would not make a pledge because we don't know what kind of emergencies can come up," Schwarzenegger told San Diego talk radio host Roger Hedgecock during an interview Monday on KOGO. "I have already made it clear that there could be things like terrorism or there could be disasters -- any one of those things where we might have to look at that option. I would not increase taxes in order to get the financial situation improved because I think it is the wrong way to go."

That's closer to the no-new-taxes pledge than Schwarzenegger was a week ago, when he cited the disaster/terrorism loophole, but did not declare taxes were off the table to deal with deficits.

But it's still not good enough. Not for Norquist and not for another supply-side conservative, Steve Moore, head of the Club for Growth.

Moore told Fox News Schwarzenegger is moving in the right direction, but he's yet to close the sale with his group or with other supply-siders. Moore said he and supply-siders such as Arthur Laffer were warming to Schwarzenegger until he picked Democrat and anti-supply-sider Warren Buffett as his chief economic adviser.

"That kind of cooled us all off," Moore said.

These conservatives appear torn. On one hand, they're excited by the prospect of a superstar Republican governor in California. On the other hand, they're uneasy about endorsing someone of opaque ideology and untested political mettle.

Why are the conservatives so important to Schwarzenegger?

Because no Republican or Democratic analyst believes Schwarzenegger can win without energizing GOP voters. So far, GOP voters appear to be more excited than Democrats, but are divided among Schwarzenegger, McClintock and Peter Ueberroth.

That's why Schwarzenegger began working the talk radio circuit this week. He has to reach core Republican voters and prove he's nearly as good as McClintock, but has something the state senator cannot offer -- electability.

"What Arnold Schwarzenegger is doing right now is appealing to the base conservative voters to show them he is a more viable alternative to Tom McClintock," said former GOP consultant Alan Hoffenblum.

So, for the first time in his life, McClintock -- a self-described political "geek" who last year made $114,000 -- has something the multi-millionaire film star wants: an energized conservative following.

McClintock's supporters devour politics, are addicted to conservative talk radio and almost never miss a chance to vent their spleen on election day. In other words, the very people who signed the recall petitions and helped fan the flames on the Internet and neighborhood shopping malls.

Schwarzenegger wants them -- and for the most part, McClintock has them.

McClintock has become something of a folk hero on conservative talk radio. He's filled up countless hours of air time with blunt and acidic assaults on the state's bloated budget, its apparent infatuation with regulations and a tax burden well above the national average.

Schwarzenegger will try to appeal to them. To get them, he may take the pledge. But the siren song of conservative support comes at a price.

Analysts from both parties believe Schwarzenegger must win the GOP vote and at the same time appeal to disaffected Democrats and moderates.

"He's been smart not to take the no-new-taxes pledge," said Gail Kaufman, a top Democratic strategist. "That means he's thinking about governing. That will impress moderate Democrats who are tired of [Gov. Gray] Davis. If he takes the pledge, they either won't vote or will drift back to the Democratic fold. Either way, it's bad for Arnold."

In Schwarzenegger's short political life, the drama surrounding the pledge is beginning to sound almost Shakespearean.

"To pledge, or not to pledge ... that is the question."