The vice presidential debate is set for next Thursday, and millions of voters will be watching to see if moderator Gwen Ifill of PBS behaves herself.

Most journalists are still getting accustomed to the Sarah Rules, as established and enforced by John McCain’s campaign team. The most important is Sarah Rule No. 1: Don’t treat Gov. Palin like a male candidate, or you’ll be accused of character assassination.

Maybe this is why McCain has kept Palin sequestered from the press — not because he’s terrified she’ll pull a Dan Quayle and say something goofy (as she did to Katie Couric), but because he gallantly wants to protect her from all the chauvinist meanies who would ask impertinent questions.

Likewise, the same right-wing gasbags who’ve trashed Hillary Clinton for 16 years have morphed into sensitive souls when it comes to their own hockey-mom candidate. Each unsettling news revelation about Palin is automatically decried as a sexist smear.

If Palin were a male candidate, Democrat or Republican, she’d be taking heat for ducking reporters when the election is only five weeks away. Yet, except for a few grumps, the media have reluctantly accepted the Sarah snub as the new order of things.

In the big debate it will be interesting to see if the rules are followed, or broken.

If Palin were a male candidate, for example, she would again be asked (as Charles Gibson did) why she took credit for killing Alaska’s notorious Bridge to Nowhere, when in fact she supported the $223 million boondoggle until Congress turned against it.

If Palin were a male candidate, she might also be encouraged to discuss why she chose a high-school pal to head Alaska’s Division of Agriculture at a $95,000 salary. Among her flimsy qualifications, the woman, a former real-estate agent, claimed an affection of cows.

If Palin were a male candidate, she’d be asked why she put another childhood friend in charge of a money-losing, state-subsidized creamery that was supposed to shut down until Palin reversed the decision. As The Wall Street Journal reported, the doomed dairy cost Alaskans more than $800,000 in additional losses before it was finally closed.

Explain $17,000 `per diem’

In fact, during her short stint as governor, Palin has appointed several school buddies to well-paying state posts. Her legislative director was in the same junior-high band with Palin. Another old classmate was operating a Mailboxes, Etc. franchise when the governor appointed him head of the state’s economic development office.

If Palin were a male candidate who claimed to be a crusading, cost-cutting reformer, she’d be asked what made her any better than other politicians who hand out fat government jobs to cronies.

Maybe if she were a male candidate, she’d be pressed to explain why she billed the state more than $17,000 as ”per diem” expenses — for 312 nights she spent at her own home.

Palin’s staff told The Washington Post that the governor is entitled to such payments under Alaskan law, but a male candidate would be quickly reminded that even members of Congress don’t receive a per diem allowance for routine home visits.

A male candidate would be asked how he could promote himself as a ”maverick” while dunning taxpayers on his expense accounts.

If Palin were a man, she’d be questioned closely about her professed aversion to pork-barrel government spending, since she has happily pledged $500 million of her state’s money toward a 1,715-mile natural gas pipeline.

Speaking about that as-yet unbuilt project, Palin got on stage at the Wasilla Assembly of God and told churchgoers: ”God’s will has to be done in unifying people and companies in getting that gas line built, so pray for that.” As you might imagine, this is a popular clip on YouTube.

A male candidate would be ridiculed — no, make that crucified — for suggesting that the Lord has taken a personal interest in natural-gas extraction. Luckily for Palin, the Sarah Rules censure such commentary as anti-religious.

Imagine if her Democratic opponent, Sen. Joe Biden, had been videotaped while being solemnly blessed against ”every form of witchcraft.” The Republicans would jump on it, running blistering ads to portray Biden as a whack job unfit for the vice presidency.

President Palin?

Wondrously, though, Palin has yet to face any questions about her weird anti-witch inoculation at the hands of one Pastor Thomas Muthee in 2005. It’s sort of creepy to watch, but who knows — maybe this stuff really works for future vice presidents. Maybe Spiro Agnew should have tried it.

Once upon a time, any person who sought the second-highest office in the land could expect to be grilled almost as unsparingly as a presidential candidate. Biden himself has been slammed during campaign interviews, not always unfairly.

Yet the Sarah Rules allow everyone to explain Palin’s words and past actions except Palin herself.

If she were a man, they wouldn’t be praising her for being a hockey dad. They’d be calling her a lightweight who shouldn’t be a hundred heartbeats from the Oval Office, much less one.