The extraordinary events of the past few days have left Hillary Clinton poised to become U.S. president, the Republican Party in a shambles and Donald Trump the champion of the unhinged fringe.

Looking ahead, one of the chief tasks of the next president will be to put the damaged American political system back together through reconciliation. Assuming she becomes that president, Ms. Clinton will need to make this her highest priority.

The release on Friday of a tape in which Mr. Trump boasted that he could and did sexually molest women with impunity because of his fame shocked the conscience of the Republican Party.

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The three dozen senior Republicans who subsequently declared that they no longer support Mr. Trump included Arizona Senator John McCain. (Every Republican presidential candidate except Bob Dole has now repudiated Mr. Trump, one way or another.)

John Thune of South Dakota, who is the third-ranking Republican in the Senate, went further by calling on Mr. Trump to step down. And House Speaker Paul Ryan divorced himself from the Trump campaign on Monday, saying he would focus instead on preserving GOP seats in the House of Representatives and the Senate.

For all intents and purposes, Mr. Trump is no longer the Republican Party's nominee, which appears to suit him just fine. Instead, he has become the candidate of the alt-right movement, the candidate of Drudge and Heat Street and PJ Media and Breitbart. If you haven't heard of some of those sites, it is because you don't traffic in darkness.

In the Sunday-night debate, Mr. Trump channelled everything that the extreme right has been advocating for years. He vowed that, if president, he would appoint a special prosecutor to investigate Ms. Clinton, assuring her that if it were up to him, "you'd be in jail."

He accused her of using the office of the Secretary of State to line her own pockets. And punching through the very bottom of the barrel, he said she protected Bill Clinton from allegations of rape and other sexual offences. He put three women whose accusations against the former president have been denied and discredited in the audience to taunt her.

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David Goldman at PJ Media explained what was really going on. "A very large portion of the electorate (how large a portion we will discover next month) believes that its government is no longer legitimate, and that it has become the instrument of an entrenched rent-seeking oligarchy," he wrote.

"… That's why it was so important for Trump to talk about jail time for his opponent. If things had not gotten to the point where former top officials well might belong in jail, Trump wouldn't be there in the first place."

It all makes sense now, including Mr. Trump's dark warnings that the election itself might be rigged against him.

Mr. Trump and his happy band of racist, misogynist, climate-change-denying, Muslim-hating, conspiracy-theorizing, birther-promoting, gun-celebrating, survivalist-embracing electoral-coup-promoters seek to broaden –and no doubt profit from down the road – the movement that denies the legitimacy of the American government.

They hope there are enough frightened, angry Americans who fear for their jobs and safety, and who blame outsiders for their troubles, to elect him as president. This won't happen. The republic remains infinitely more robust than these hate-fuelled fringers believe.

But it does leave American politics in a parlous state. The GOP today is divided, discredited, disgraced and soon to be defeated. This is very bad for American democracy, which depends for its health on two credible political parties.

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There is hope. Gordon Giffin, who was U.S. ambassador to Canada under Mr. Clinton, has suggested that Ms. Clinton could incorporate into her administration senior Republicans who disavowed Mr. Trump. These figures could help a Clinton administration forge bipartisan compromises on immigration reform, campaign-finance reform, trade promotion and action to fight climate change.

Such successes would not only be good for the United States and for the Clinton presidency. They also would allow the Republican Party to heal, to lift its head and to pursue a path of principled conservatism, rather than simply nihilistic obstruction.

Yes, it's early to be talking about such things. But with the Trump campaign having finally bolted beyond any pale, we might as well get the conversation started. It's all we'll be talking about after Nov. 8.