Trump has been warning of potential election fraud for weeks and his party is trying to push through a Supreme Court nomination while people are actually early voting.
The debate contained snatches of substance amid snowballing chaotic and aggressive exchanges between Trump and his Democratic challenger, former Vice-President Joe Biden, and moderator Chris Wallace of Fox News.
It started with a tense Trump and a smiling, mostly disciplined Biden determined to hold his own, and then rapidly went off the rails.
Both began interrupting each other and trading jabs. After an initial discussion on the Supreme Court, Biden was muttering "will you shut up, man" and trying to appeal directly to voters straight to the camera.
Biden's points on Trump's handling of the coronavirus and the economy - including lines such as "you are the worst president America has ever had" and "it's hard to get any word in with this clown" - helped Trump boil over.
"Frankly, you've been doing more interrupting," Wallace told Trump at one point.
Constantly trying to land blows - "there's nothing smart about you, 47 years you've done nothing" - Trump forcefully hammered Biden on law and order and accused his opponent of being trapped by the "radical left".
Biden was steady and engaged enough to adequately get through a difficult situation despite a brief period where he looked flustered. But it was really a win for Biden's calmer demeanour over Trump's off-putting shoutiness. Personality squashed policy and the messy spectacle made America's reputation a loser.
With the election in just over a month and early voting already under way, Biden was aiming to lock in his frontrunner's advantage into the home stretch. The debate would not have helped Trump win back suburban women, a key voting group.
Biden is heading a large unwieldy coalition of voters and activists, united more by the idea of turfing Trump out than enthusiasm for his own candidacy. Polls show that both sides are energised to vote, regardless of motivation.
For his part, Trump wants to keep his most devoted fans simmering, attempt to deter would-be Biden voters, bring waverers home and find new supporters.
As much as thoughts of 2016 are hard to shake off, this is a different scenario.
Biden is running ahead of Hillary Clinton's results in 2016 and is a less controversial figure. Trump has suffered some slippage in support from when he won before. Views are mostly baked-in, the polls have been less volatile than four years ago.
Back in the primary season, Democrats picked Biden to do a specific job: Take the fight to Trump where the Republican was most devastating in 2016, in the Rust Belt states of Pennsylvania, Michigan, and Wisconsin.
A son of Scranton, Pennsylvania, Biden seems suited to the task. He is polling better at this stage than any US presidential candidate since Bill Clinton in 1996. He is outpacing everyone since 1976 except Clinton and Ronald Reagan in 1984. At his best he has Clinton's ability to cut through, explain and be empathetic.
But caution is still absolutely required. People are having to vote during a pandemic in a country where infections are widespread and on the rise. Results will be incomplete on November 4 NZT. 'What will Trump do if he loses?' is a major questionmark.
A polling trend that most Democrats intend to vote early and by mail whereas Republicans are more likely to wait for election day is already been borne out.
The Washington Post reports today that more than nine million voters have requested mail ballots so far in Florida, Pennsylvania, North Carolina, Maine and Iowa. Data shows 52 per cent were Democrats, 28 per cent were Republicans, and 20 per cent independents.
The Post cites internal Democratic and Republican data to report a similar trend is occurring in Ohio, Minnesota, New Hampshire and Wisconsin.
The swing states will be 3 to 4 points tighter than the national polling average. And the Electoral College system means Biden would need at least a 5 per cent edge in the popular vote to be confident of victory.
Today was only round one of a month of scheduled bruising battles.