A man arrives to vote on Election Day. (Frederic J. Brown/Agence France-Presse via Getty Images)

Michael F. Cannon is a resident scholar at the Cato Institute.

Hillary Clinton’s decision to join Green Party candidate Jill Stein’s recount efforts in key states may have been welcome news to Democrats, but it is unlikely to change the outcome of the presidential election. Nor will complaining about the unfairness of the electoral college or begging Republican electors to vote for Clinton. Democrats’ best chance to prevent Donald Trump from assuming the presidency is instead to do the unthinkable: Throw their support behind another Republican, such as Mitt Romney, the former Massachusetts governor and 2012 GOP presidential nominee.

To become president, a candidate must get a bare majority of 270 votes when the electoral college meets Dec. 19.

As Alexander Hamilton explained, the electoral college provides a backstop in the event voters select a dangerously unfit candidate. “The process of election,” Hamilton wrote, “affords a moral certainty that the office of President will never fall to the lot of any man who is not in an eminent degree endowed with the requisite qualifications.” Electors would use their judgment to prevent the “tumult and disorder” that would result from “this mischief” of presidential candidates exploiting “talents for low intrigue, and the little arts of popularity.” One might call it the cooler-heads college.

Election Day produced 306 electors pledged to Trump and 232 pledged to Clinton. A petition at Change.org asks Republican electors to vote for Clinton. A group calling itself “Hamilton Electors” seeks to persuade at least 37 GOP electors to vote for a Republican other than Trump, leaving him with only 269 votes. If no candidate secures 270 votes, the House of Representatives selects the next president from the top three vote-getters in the electoral college.

Either strategy is a fool’s errand. Whatever reservations Republican electors may have about Trump, empty entreaties from Democrats are unlikely to sway them. Even if 37 Republican electors voted for another Republican, the GOP-controlled House would likely select Trump anyway.

The only way Democrats stand any chance of persuading Republican electors to abandon Trump is with a dramatic gesture of true bipartisanship. If all 232 Democratic electors pledge to reach across the aisle and vote for a Republican alternative to Trump, it would take just 38 GOP electors to make that person the next president.

If Clinton announced she is releasing “her” electors and asked them to vote for a credible Republican alternative, she could plausibly deliver all 232 Democratic electors. She might even secure similar pledges from House Democrats in the event the election went to the House.

Republicans and Democrats react to the announcement that Hillary Clinton’s campaign plans to join a vote recount in Wisconsin initiated by former Green Party presidential candidate Jill Stein. (Bastien Inzaurralde/The Washington Post)

Finding 38 Republican electors might then be easier than Democrats think. In 2012, Romney won a larger share of the popular vote (47.2 percent) than Mr. Trump did this year (46.2 percent). There are 35 Republican electors from states where Romney got more votes than Trump (Alaska, Idaho, Kansas, Mississippi, Utah, Wisconsin), and at least 120 others from states where Romney won a larger share of the vote. That’s more than half of Republican electors. Texas has 38 electors all by itself.

Naturally, most rank-and-file Democrats would consider the idea of backing a Republican for president abhorrent. Even so, the electoral college presents a most interesting test for Clinton and her party.

If Democrats believe Trump poses a unique threat to the republic, and signal this is not okay by reaching across the aisle to marginalize and stop him, then win or lose, Democrats could legitimately claim they put partisanship aside for the good of the country.

If Democrats believe Trump poses a unique threat yet don’t support another Republican in the electoral college, it will indicate that Democrats see Trump as no different from any other Republican. And if Democrats treat Trump as normal, they will be complicit in normalizing his behaviors.

The only people who will be responsible for a Trump presidency are those who voted for him — plus Clinton and her campaign, who helped to raise Trump’s profile during the primaries. But if Democrats truly believe what they say about Trump, they should prefer another Republican who does not threaten to normalize what a Trump presidency would.