SAN FRANCISCO — A few days after Arnold Schwarzenegger announced his run for governor, Fox News pundit Brit Hume sounded hopeful.

“California is a special case,” he said, “a place where conservatives and Republicans have been doing nothing but suck canal water now for a decade or so. And their standards of how pure you have to be, I think, are going to be very forgiving in this race, which will help Schwarzenegger.”

Such predictions ignore a subterranean reality: Mr. Schwarzenegger’s candidacy threatens to expose a deep fault line below the surface of long-standing GOP ideology — the disconnect between championing “the free market” and extolling the centrality of “family values.” Nowhere is that fissure more extreme than in the realm of mass entertainment supplied by media conglomerates, and no political aspirant could better personify the contradiction than Arnold Schwarzenegger.

Widely seen as part of modern-day Americana, the gratuitous violence and sexual imagery of trademark Schwarzenegger movies are anathema to many religious fundamentalists and social conservatives. Those films may be commercial hits — since the mid-1980s, a slew of them have grossed a total of well over $1 billion at the U.S. box office — but they are apt to be deeply troubling to an array of voters, including many who are crucial to the Republican base.

Candidate Schwarzenegger seems to be tone-deaf about such concerns.

“In everything I ever did, I showed great leadership,” he boasted to reporters after filing papers at the Los Angeles County registrar’s office. “There were times when people said it could never be done, that an Austrian farm boy can come over to America, and get in the movie business, and be successful. … And you know what happened? I became the highest-paid entertainer in the world.”

In the Republican lexicon, becoming the “highest-paid” anything is usually laudable. But, in this case, not necessarily.

Like the huge media firms cashing in on his boffo performances, Mr. Schwarzenegger has profited handsomely. But many self-described conservatives, while agreeing with his adulation of lower taxes and the power of the free market, surely dislike Mr. Schwarzenegger’s persona as an entertainer. They may find it impossible to separate that persona from his new on-screen work as a political candidate. The Schwarzenegger image, relentlessly marketed over the years, will make it extra difficult for the would-be governor to build bridges to conservatives who differ with him on abortion and gay rights.

For decades, the Republican Party has carefully threaded a pair of ideological needles — often denouncing the libertine media products of a “free market” that the party never tires of boosting. For the most part, GOP leaders have been able to finesse the dilemma by lavishing praise on the unfettered quest for profits while selectively condemning some of the results in mass entertainment — the kind of multiplex movie fare and prime-time TV programming that fill America’s screens with salacious content.

This summer’s battle on Capitol Hill over the latest Federal Communications Commission push to further deregulate the airwaves is an indication that time is running out for politicians to evade such contradictions. Spurred into action by the accelerating trend toward more centralized media ownership, a de facto coalition spanning left and right — including social and religious conservatives — bucked the White House with an overwhelming House vote to roll back some of the FCC’s latest moves to let enormous media firms consolidate even more power.

When Mr. Schwarzenegger talks about his love of “free markets,” none of the GOP faithful will mind. But when, in the political arena, he becomes a daily in-your-face reminder that media conglomerates have more power than ever to saturate TV sets, computer screens, video racks and theater chains with profit-driven entertainment that many parents and other Americans find deeply objectionable, the contradictions may seem too close to home and too glaring for comfort.

That’s a key reason why, for the Bush administration, Mr. Schwarzenegger could turn out to be a dangerous symbol of capitalist mega-media run amok — and a lightning rod that draws unwelcome heat to the simmering tensions between free-market rhetoric and more distasteful media realities.

The GOP pols backing Mr. Schwarzenegger may believe that California’s conservative voters are ready to “suck canal water” in order to get a Republican into the governor’s office. But the candidate may end up serving as an embodiment of media swill that seems too distasteful to swallow.