Republicans elites feel so entitled to the Alabama Senate seat that Jefferson Beauregard Sessions III vacated to become Donald Trump’s attorney general that they are meticulously neglecting the easiest strategy for keeping Roy Moore out of the Senate.

Senate majority leader Mitch McConnell has called on Moore, the scandal-plagued former judge who now faces multiple allegations that as a 30-something prosecutor he molested teenage girls, to quit the Alabama race. But Moore’s not quitting. In fact, he says McConnell should resign.

So DC Republicans are spinning complex scenarios for keeping Moore out of their caucus. The scenarios have grown increasingly arcane, and unworkable. But the keep coming.

There has been speculation that if Moore is elected in the December 12 special election, he could be seated and then expelled. But there’s no guarantee that it will happen. Expulsions are rare, and there’s a reason for that: A super-majority of senators—two-thirds of the chamber—is required to overturn an election result.

There have been suggestions that appointed Senator Luther Strange—the guy Moore dispatched in an August Republican primary—could resign and in so doing create a vacancy and would restart the process that began when Sessions quit. Or that Alabama’s Republican Governor Kay Ivey could change the election date in order to give the Alabama Republican Party a sufficient window in which to replace Moore as their nominee. But Alabama Republicans appear to be determined to stick with Moore—and the December 12 election date.

Then there are the proposed write-in campaigns: for Strange, for Sessions, for just about any Republican except Moore. But write-in victories are almost as rare as expulsions. And the wrong strategy for a write-in run could end up splitting the anti-Moore vote.

It’s likely that McConnell and his compatriots will proposing convoluted political “fixes.” But none of them will be certain, or in some cases even likely, to block the judge.

There is, however, a simple and politically viable way to keep Moore out of the Senate: Back the candidate who is most likely to defeat him on Election Day.

Moore faces a credible opponent in Democrat Doug Jones, a former US Attorney with a distinguished record of defending the rule of law and prosecuting the violent racists who were responsible for the 1963 bombing of Birmingham’s 16th Street Baptist Church. He is running a strong campaign; indeed, some polls are now giving him the lead in this intense contest.

Jones has been endorsed by a number of grassroots Alabama Republicans; he is even running television ads featuring them.

There is a very long history in American politics of voters crossing partisan lines to reject candidates they object to—or to support candidates who impress them. The 1924 Democratic nominee for president, corporate lawyer John Davis, frequently endorsed Republicans who were running against Franklin Delano Roosevelt. There were “Democrats for Eisenhower” groups in the 1950s, “Republicans for Johnson” groups in 1964 and “Democrats for Nixon” groups in 1972. Bill Weld was elected governor of Massachusetts in 1990 because a lot of cross-over voters preferred his libertarian-leaning Republicanism to his Democratic opponent’s social conservatism. And Barack Obama ran in 2008 with a long list of endorsements from prominent Republicans and former Republicans.

There are contests where it is ethically necessary to put aside partisanship and back a candidate from another party. There are also times when it is politically practical to abandon your party line for one election.

The Alabama contest meets the ethical standard, and the practical standard. A few wise Republicans recognize this. Asked last week if he would support a Democratic candidate over Moore, Arizona Senator Jeff Flake replied: “If the choice is between Roy Moore and a Democrat — the Democrat, no doubt.”

Flake added: “I would literally — if I were in Alabama — I would run to the polling place to vote for the Democrat.”

The choice in Alabama, as its stands now, is between Republican Roy Moore and Democrat Doug Jones.

If Mitch McConnell and his Republican allies are serious about keeping a reprehensible Republican out of the Senate, they don’t need convoluted strategies. They need only to recognize the reality of their circumstance—and the logic of the electoral calculus that Jeff Flake had already explained.