Trump does not function from a position of fear in anything he does. But he does not for a moment doubt that the Dems will do everything and anything , legal or not, to sway the election in Biden's favor.
It's gotta be at least a 6.. But the Donald doesn't show much fear & I'm sure he thinks he's got all the answers & the Trump enclaves are very confident, so I imagine for them & Donald it's about a 1 or less. Given the shape that the world is in & that we're entering a time when Ol Joe doesn't really have to campaign, just let ole Donny shoot off his mouth & his tweeter, it should be a 10
Trump is probably concerned but Joe Biden is beatable. It's not like Trump is up against a politician of the caliber of Reagan, Clinton, Obama, or Kennedy. Biden is about on par with politicians like Kerry.
I'm middle of the road which gives me the ability to actually see what's going on with politics.with that said, The reason Trump got elected is the same reason there are hardcore Bernie lovers... People want something different.
One a scale of 1 to 10, it's definitely a low number. That might not be the answer you want to hear but that's reality.