The election is too far off to be forecasted with polls right now. Lots of things could happen; Trump and Kim could have a nice summit and make an earnest deal; Iran could attack another tanker and this time people are killed; China could buckle under the tariffs; the economy could suddenly tank; we've got all sorts of investigations going on; maybe Pelosi loses control and they start impeachment proceedings...
I did read a story on how different Trump's campaign will be this time; the Trump campaign has instituted all sorts of training programs for volunteers, has a very effective small donor fundraising process, and an greatly improved "ground game", additionally this time around there's more solidarity among the Republicans. On the other hand, he campaigned as an outsider, now he stands astride that swamp. From what I gather Trump realistically confronts either Biden or Bernie. Biden is the blandest of moderates, so Trump has to position himself as more of a maverick, with Bernie (Harris, Buttigieg, Warren, Booker, Beto...) its just let them explode in their own Marxist delusion.