California Republicans are headed for a showdown over the direction of the party that could highlight national schisms over gay rights, gun control and abortion.

Gov. Arnold Schwarzenegger wants the state GOP platform — the party's statement of core values — boiled down to as little as a single page focusing on lowering taxes, limiting the size of government and building a strong national defense.

A centrist, the actor-governor describes himself as a "post-partisan" who wants to bridge the political divide that often leaves the state capital of Sacramento gridlocked.

But some conservatives see his move as an attempt to undercut party positions on everything from traditional marriage to opposition to abortion rights.

"There's a move afoot to make sure the Republican Party stands for nothing," said Michael Spence, president of the conservative California Republican Assembly. It's "a direct assault on Republican Party principles. They think they can reduce the party to a few lines or sound bites."

State party members will begin work on a new platform later this week at the state convention. In a sign of internal differences, a platform draft being circulated by state GOP chairman Ron Nehring goes well beyond the trimmed-down framework suggested by the governor.

Schwarzenegger is circulating a letter, also signed by Republican leaders in the legislature, that says the platform should be distilled to a page or two of concise principles echoing those held by Ronald Reagan.

The current state platform runs about a dozen pages and opposes gay marriage and domestic-partner benefits; calls for overturning the landmark Roe v. Wade decision that established a constitutional right to an abortion; and opposes gun registration.

The governor's letter makes no mention of those issues.

"We have found long recitations of detailed policy statements are unwieldy, hard to follow and for the most party unread by the very people we want to share our core beliefs with," the letter said.

Nehring said the party was in the midst of a "healthy discussion" on its future.

"This is normal for people to express different views," Nehring said. His draft platform states that marriage is "one man to one woman" and that society must protect "the unborn."

Republican moderates in the state have long argued that the party needs to shift to the political middle or risk becoming an afterthought in a state known for its increasingly diverse population and Democratic leanings. The legislature, for example, is firmly in Democratic hands.

Schwarzenegger's re-election last year was largely attributed to his move to the political middle ground, a decision that created a rift with the GOP right wing.