Bush won a close election. Subsequent investigations established that the Supreme Court decision likely didn't make a difference.
https://community.cbr.com/showthread...re#post1725850
He does have some stuff going for him.
Incumbents typically win reelection, especially when their party has been in the White House for only one term (Jimmy Carter is the only President whose party was kicked out of the White House after just one term in the last 120 years.)
When he ran the first time around, Republicans were suspicious that a guy who was a registered Democrat during the George W Bush presidency might be a secret liberal. Now he has a conservative record on things that matter to the party faithful (judges, taxes, regulatory overreach) in addition to his existing fan-base.
His approval rating was relatively consistent in the low-40s, which was always enough to be credible against a flawed opponent (IE- a Democrat painted as wanting to allow employer-funded health insurance.) And that was before the Mueller report removed some of the worse-case scenarios from voters' minds.
A recent political trend is that Democrats have stopped dominating in special elections, which suggests that what happened in the midterms doesn't necessarily prove that voters want Democrats want voters in charge.
https://politicalwire.com/2019/03/20...lection-magic/
https://www.politico.com/story/2019/...ection-1230495
Consumer confidence is also high. 71 percent think the economy's in good shape.
https://www.foxnews.com/opinion/trum...2020-democrats
There have been no major crises. And Democrats are taking some unpopular positions (in favor of late-term abortion, etc.) heading into the next presidential race.
There are a lot of unknowns. The Southern District US Attorneys might find something, as could the New York Attorney General. Trump might react poorly to some kind of national crisis. A Democratic presidential candidate could navigate through the divides in the primary, and avoid taking positions that freak out the center or alienate major voting constituencies. But it's certainly possible for an incumbent President to win a second term, especially when he just got good news following an investigation.