The start of the winning?
On immigration, maybe. I never understood why Democrats thought they'd be able to pull off sanctuary cities with Trump willing to withhold federal money. I'm not convinced they can hold out, or even if they are willing to. So far their resistance to ICE has largely been cost-free, but once those funds dry up I imagine there will be a change of heart.
I'd dare to claim that immigration, good economy (thanks, Obama!) and bombs here and there in ME would be pretty much enough for re-election and probably even for midterms.
Business cycle. Google the average business cycle length and then formulate whether the good economy will be there by the re-election.