Some polls are just plain bad, in both directions. I would focus on things like the RCP (Real Clear Politics) average. Take Michigan for instance, where polls range from +6 to +12, and RCP's formulated avg. is 8.4. I ignore that number, instead check out the % for each candidate. Biden is at 49.6, Trump is at 41.2. Biden is literally polling at 50%, with TEN 10% of the poll undecided.
Now, there's a margin of error and maybe some people lie to pollsters, whatever. There's a second consideration, which is vital. There are no moderately known 3rd party choices this year, none. I have no clue who the Libertarian or Green Parties will nominate. It doesn't matter, they're nobodies, similar to 2008 or 2012 most recently. That is quite important, because that makes it even more of a binary choice. For argument's sake, there's 7% undecided in MI avg polling. Let's give Donny an edge 4-3, and say Biden really is favored around 52-45 there. So you mean to tell me voter suppression, lying to pollsters, whatever, will erase a SEVEN point edge? I'm sorry, that simply does not happen.
Clinton's RCP lead in MI was around 4% for most of the time, but that's with a significant 3rd draw to Johnson and Stein of nearly 7%. Hillary/3rd party's lost 4% in the final results, with Trump moving up 5.5%. A big chunk of people either did not bother to vote for Hillary or opted at the last juncture to say eff it and voted for Trump. The state's electoral results since 2016 have been a 180, totally against Trump/GOP. That's one state, but there's a consistent scenario in many other states which Biden currently holds leads in.
Trump has begun to attempt to act like he's serious about the CV-19 and whatnot. Here's his problem. He needs to keep that up for nearly THREE months without unleashing utter nonsense during briefings. The cancellation of the campaign tour is obviously a big help to gaffe-prone Biden, but it's also a plus for Trump. There's fewer chances for him to go lunatic in a speech since he's got no crowd in front of him expecting red meat. My prediction is his convention speech is a complete meltdown of vitriol, and that's basically the end of the campaign right there, well before any debate meltdowns.