The Election itself? Not at all, I'm fully confident Biden will get enough votes to win. The war afterwards, and Trump and the GOP shutting down the election and declaring the Democracy over? Yeah pretty damn worried about that, especially because the repeated line for why Trump won't overthrow the election has been "Boy howdy lets hope he doesn't."
Even if the government stands and somehow Biden is allowed to take the oath of office, I don't think the nation will ever be the same. We're going to have entire states that don't recognize the president as valid, entire branches of Government that won't recognize the president as valid, and thousands if not more armed militants who truly, in their heart of hearts, think its their patriotic duty to kill Democrats and retake the country from Liberals. I think we're gonna be looking at a lot of attacks, shootings, assassinations, mass armed protests and I wouldn't put it past Trump cultists to storm the White House with guns and a shoot-out takes place in an attempt to kill Biden or Harris.
And this is to say nothing of what Trump will do if he loses and actually leaves office. He'll set up a fake oval office and do 'presidential' addresses where he orders the GOP to do X or Y, and they'll listen to him. He'll be a president in exile, without the exile part. He'll just assume the role of the second president and 40% of the country will listen to him.