It's the economy, stupid. If people have jobs, and they aren't being taxed as much as the other side is going to tax them, then they're going to vote for the devil they know.
And no amount of telling people that they are wrong or stupid for voting Republican is going to change their mind.
While I agree that telling people they are wrong and stupid will do little to change their mind, I think repeating "it's the economy, stupid" is the lazy pundits approach. Despite one of the best economies ever, DJT's struggled to rise above the 40% approval rating, and more his disapproval rating has remained north of 50% for over two years. No other president has had the majority of Americans disapprove for as long and win election. Reagan had a net unfavorable rating for a few weeks, but that was during a big recession.
One could correctly say that DJT remains historically unpopular despite a roaring economy and what may soon become the longest economic expansion in US history*.
I don't look at factoids like "DJT has the support of 90% of GOP voters" and think that's a strong bulwark for him, as about 60% of the country is
not republican. Not coincidentally, that's how you get approval ratings in the upper 30%s... you get 90% support from your party 95% disapproval from everyone else.
Ultimately what matters will be turnout. The GOP, with their older and more affluent voter base unquestionably has higher voter turnout in election after election. The question becomes 'will it be enough to overcome the broader (and deeper) negative opinions on this administration?'.
*give credit where credit's due; the majority of this expansion occurred under Obama, following the 'great recession'.