The White House is doing its level best to tamp down passionate calls from conservatives to pardon perjurer I. Lewis “Scooter” Libby, but protecting Vice President Dick Cheney’s former chief of staff from going to prison might prove to be politically unavoidable.

As a matter of honor owed to a loyalist who jeopardized everything to protect the White House — and for the political expediency of avoiding a lengthy public debate while Libby appeals — a quick presidential pardon could be the least-awful choice in what’s become a miserable mess for George W. Bush. The more emphatic alternative, considering how the Libby trial made clear that Cheney is at the center of this mess, would be for Bush to ask his vice president to step down.

The option Bush didn’t choose, at least not last week, was to join the conservative chorus seeking to discredit as a political sham Libby’s conviction for lying in the federal investigation of the leaking of a CIA operative’s name. A day after the verdict came down, the president voiced unequivocal support for the legal process that ensnared a top White House adviser. “This was a lengthy trial on a serious matter and a jury of his peers convicted him, and we’ve got to respect that conviction,” Bush told a CNN interviewer.

In other ways, too, the president and his team made it clear they would not fan the flames of what became a conservative tirade against the verdict and the federal prosecutor, Patrick J. Fitzgerald, who won it. Presidential spokeswoman Dana Perino dismissed talk of a pardon as “hypothetical” and Bush himself said he was “pretty much going to stay out of” the case while Libby appeals.

None of this, of course, closed the door on a pardon sometime in the final 22 months of this presidency, and it’s quite possible that Bush’s camp realized the risks of encouraging such talk so long as the case remains front-page news.

To many critics of the administration, the principal argument favoring a pardon is counterintuitive: That it might very well be the most honorable thing for the president to do — if Cheney himself continues to decline to publicly explain his own role in the White House leak of the name of CIA operative Valerie Plame soon after her husband, former Ambassador Joseph C. Wilson IV, sought to refute an administration’s rationale for the Iraq War. The facts of this case more than suggest that Libby lied to protect his boss, the vice president. In the eyes of Bush detractors, letting Libby go to jail for his loyalty would make Bush seem like a heartless jerk.

If Libby’s appeals drag on and if he goes to prison, the Democrats who now control Congress — and who see their oversight powers as their best cudgel against the White House — would have plenty of incentive to try and compel Cheney to answer some troubling questions: Why did he tell his top aide that Plame was married to Wilson, who was then bedeviling administration claims of uranium sales to Iraqi dictator Saddam Hussein? What did Cheney want Libby to do with that information?

The respectable presumption, rebuttable only by the vice president himself, is that Libby outed Plame at Cheney’s behest. Once hearing the news from Cheney, Libby passed it on to reporters and other government officials. And so the ultimate question for the Democrats to ask is this: Is that what Cheney wanted? If it was, then the vice president would arguably be involved in the illegal outing of a covert agent.

Libby initially asserted he had not learned about Plame from Cheney, then changed his story and said he’d forgotten about their conversation. For the story to become clear, congressional Democrats will have to take the lead in pursuing a more sinister explanation for Libby’s bumbling effort to keep his boss’s involvement under wraps: that Cheney was personally vested in discrediting Wilson because the vice president wished to cover up the notion that he’d knowingly let the president repeat a bald inaccuracy as part of the case for going to war.

It appears that no prosecutor is going to touch that one, as Fitzgerald proved. And congressional scrutiny of the administration has clearly been rediscovered at the Capitol now that Democrats are in charge, as evidence by last week’s hearings into the shoddy conditions for wounded soldiers at Walter Reed Army Medical Center and the political reasons for the recent firings of several federal prosecutors. However, Democratic leaders have so far shown little appetite for opening a high-profile and potentially debilitating investigation of Cheney so late into the administration’s lame-duck years. Besides, many of them believe, there is little need to further stir the pot when the White House is in full boil on its own.

Still, the longer Libby’s case stays in the news, the more it could lead to Cheney’s door. The longer the public has reason to think about whether Cheney had a hand in possibly deceiving Congress into authorizing the war, the more pressure there will be on Bush to either pardon Libby or get rid of Cheney to stanch the talk.

Contributing Editor Craig Crawford is a news analyst for NBC, MSNBC and CNBC. He can be reached at ccrawford@cq.com.