Here’s how to become a principal in Washington: be unprincipled. In order to stand any chance of advancing to leadership, one must lead from behind, thrusting the finger in the air to gauge which way the wind is blowing and then raising that other finger in defiance of a core belief in anything. Time and again, we witness the political rats abandoning a ship when they think it’s sinking only to climb back aboard when they determine it’s not.

The latest ship is the USS Roy Moore. In this case, the “USS” stands for “United States Senator,” which the polls of voters show is increasingly likely after the special election is held in Alabama Tuesday. Never mind that he stands accused of child molestation and otherwise hitting on young girls nearly 40 years ago. They were teeny-boppers, and apparently quarry for a man who was then in his 30s. That’s how the charges went, at any rate — charges credible enough that Republicans, even though desperate to maintain their thin majority in the Senate, still were demanding that Moore abandon his campaign lest they be splattered by the same stain of immorality. But now, they’re displaying their amorality.

The Republican National Committee, supposedly the party establishment’s club, had shut down its support for Roy Moore when it looked like he’d be chewed up and spit out by the perv allegations. But Moore’s Christian fanaticism has served him well in Alabama through a long career of ups and downs. His frequently expressed belief that the fundamentalist version of God takes precedence over the nation’s fundamental charter, the Constitution, has endeared him to the religious zealots who make up the bulk of the state’s electorate.

Roy Moore adamantly denies all the charges, and blames them on the “fake” media and the GOP establishment. Sound familiar? Now that the polls seem to indicate that he’ll survive the scandal and defeat Democrat Doug Jones, the RNC and most of the party leaders who had tried to dump him are now undumping him. The Republican National Committee is sending money into the state for get-out-the-vote efforts, and so many of the heretofore harshly critical senators and other illuminaries are now insisting that “the people of Alabama should decide” whether Moore becomes Sen. Moore. They mumble about an Ethics Committee investigation into whether he should stay, but they know full well that it wouldn’t go anywhere. And neither would he. Put another way, they decided that political expedience trumped right and wrong.

Yes, the word “trumped” was a chintzy segue to President Donald Trump. POTUS had avoided the whole subject of Roy Moore once the accusations of puberty stalking emerged. Trump is credibly accused of all manners of sexual imposition himself. Then, of course, there was his confession of groping on the “Access Hollywood” tape. So when it came to Roy Moore, he was making himself scarce. But now we have the polls that show Roy Moore beating the rap. Predictably, there was the president stopping for cameras outside the White House to declare he’d endorse Moore. After all, having a guy on your side accused of sex crimes is preferable to a Democrat like Doug Jones. Republicans need every vote they can get to succeed with their tax agenda to rob from the poor to give to the rich.

Contrast the Republicans’ complicity with the Democrats’: In the House, John Conyers, one of their icons after his more than five decades in Congress, crashed under the weight of accumulated sex charges. On the Senate side, Al Franken (yes, we’re related) was trying to hang on to his seat by his fingernails. But his colleagues stomped on his hands, forcing him to let go.

That leaves the Republicans to explain why their politics as usual doesn’t make them Roy Moore enablers — if not accomplices.

Bob Franken is a longtime broadcast journalist, including 20 years at CNN.