Two photos show President Donald Trump and former Vice President Joe Biden...

Two photos show President Donald Trump and former Vice President Joe Biden during the first presidential debate on Tuesday at Case Western University and Cleveland Clinic, in Cleveland, Ohio.  Credit: AP/Patrick Semansky

Of the many lowlights in Tuesday night’s train wreck of a presidential debate, the most significant came at the bitter end, when the president of the United States refused to say he would accept the results of the November election.

No previous president has tried to subvert our elections in the 230 years our nation has successfully conducted them. By continuing to sow distrust with false attacks on mail-in voting, President Donald Trump is traveling a dangerous road. Free and fair elections are foundational to our democracy. Destroying their integrity risks destroying our democracy.

There are many election topics worthy of debate, from the coronavirus and the Affordable Care Act to the Supreme Court, the economy and climate change. But 33 days from Election Day, the most consequential issue on the table is the legitimacy of the election itself.

For months, without citing any actual evidence, Trump has railed against mail-in voting, which is being embraced this fall by tens of millions of Americans worried about the pandemic. Mail-in voting has worked well for years in Democratic and Republican-led states where it is the routine method of voting. FBI Director Christopher Wray recently told Congress that the agency has seen no evidence of any national effort at voter fraud.

Will there be problems? Probably. There are in any vote. But they typically are isolated, evidence of neither conspiracy nor fraud but rather the mistakes that happen in such a massive endeavor.

Trump’s debate-night call for poll watchers to look for fraudulent voting had an ominous tone. Trump supporters recently disrupted early voting in Virginia with chants, flag-waving and a human barricade outside the polling site that voters had to walk around to cast their ballots. State governors need to safeguard polling stations against such intimidation, and keep anyone with weapons, especially unconcealed ones, far away. Poll watchers are needed in any contest but they must be people with skills to do the job, not random residents threatening to turn the constitutional right to vote into running a gauntlet.

These are not hypothetical worries. Asked by debate moderator Chris Wallace of Fox News to tell his supporters to remain calm as mounds of mail-in ballots are counted, Trump declined. Worse, as part of his disgraceful refusal to condemn white supremacy and allied hate groups, Trump delivered a chilling message to one such group with a history of street violence, the Proud Boys. "Stand back and stand by," Trump said. Stand by for what?

Trump tried to clean up his remarks on Wednesday, but his inconsistency on the topic risks emboldening these groups who are preening from the newfound attention. Incendiary language that boosts skepticism and anger risks starting a fire Trump might not be able to put out.

The president has a clear duty: to assure the nation that he will accept the results of the election, whatever they are and whenever they are announced. The oath he took demands it. Our democracy depends upon it.

— The editorial board