The much-anticipated first presidential debate of 2020 hit new lows on Tuesday night, and not just because of President Donald Trump's bullying and incessant interruptions of both Democratic opponent Joe Biden and Fox News moderator Chris Wallace.

Trump was responsible for some moments that represent a nadir in modern presidential debate history, starting with his refusal to explicitly condemn white supremacy, a growing domestic threat. It should have been an easy question to field. Wallace asked, "Are you willing tonight to condemn white supremacists and militia groups and to say they need to stand down and not add to the violence … ?"

Trump initially replied, "Sure," but quickly negated it by saying, "I would say almost everything I have seen is from the left wing, not the right wing." He then demanded to know specifically whom he should condemn.

When Biden volunteered, "Proud Boys," a violent, neo-fascist hate group, Trump responded, "Proud Boys, stand back and stand by, but I'll tell you what, somebody's got to do something about 'antifa' and the left because this is not a right-wing problem, this is a left-wing problem."

Within hours, the Proud Boys group, which has sparked violent clashes in several cities, incorporated "Stand back and stand by" into its logo. A forthright, unambiguous and much-needed presidential denunciation of white supremacy and violence once again was rejected in favor of a muddy message that some are taking as a clear signal to the very groups the president was asked to condemn.

On Wednesday, trying to clean up his own mess, the president told reporters he didn't know who the Proud Boys were — an unbelievable claim.

During the debate, Trump also continued his baseless attacks on the integrity of the American election system, deliberately sowing doubt about a fair election and intimating that he expects it to land at the U.S. Supreme Court.

Trump's lies about widespread voter fraud have been debunked again and again, including most recently by FBI Director Christopher Wray.

Trump again urged his supporters to act as self-appointed poll watchers. This is problematic for a number of reasons. Legitimate poll watchers who work to monitor election proceedings are appointed in advance, with each state determining its own method.

Those who simply show up at polls to challenge voters are far more likely to be engaging in voter intimidation. That prospect is particularly worrisome in this election cycle, the first presidential election since the expiration of a nearly 40-year-old federal consent decree that prevented intimidating practices in the name of ballot security. As a result, the Republican National Committee said it has recruited up to 50,000 poll watchers nationwide.

On Wednesday, Minnesota Secretary of State Steve Simon used Twitter to clarify state law on poll-watching: "Only one per major political party allowed, appointed by written certificate." Challenges to voters, he noted, are permitted only if based on "personal knowledge," not a "hunch" or "feeling."

Minnesota voters need to be reminded that there are laws in this state protecting their right to vote and opposing voter intimidation. A president for all Americans would uphold those rights.