Trump's in your face, bullying, obnoxious persona is in my opinion the main reason he will lose in November. Not his policies or what he has done or hasn't done as president, but his unpresidential behavior. Strange as it may seem, looking at independents who are fairly split on Trump's policies and stances on issues, for some, against some, but really dislike him as a person. Only 24% of independents like Trump as a person, 48% dislike him. This is important as folks usually don't vote for someone they dislike.
Now we know by historical averages that 90% of Republicans and Democrats will vote for their party's candidate regardless of who it is. Independents are finicky and at times have huge sways depending on their likes and dislikes and perceptions. Trump is in the white house because he won the independent vote in 2016, he'll probably be gone as he's about to lose those same voters. In my opinion anyway. Biden's big advantage over Hillary, he isn't as dislike by independents as Hillary was.
It's high past time that we start electing Americans to congress and the presidency who put America first instead of their political party. For way too long we have been electing Republicans and Democrats who happen to be Americans instead of Americans who happen to be Republicans and Democrats.