Trump is quite unpopular in Iowa now per the latest poll.
But he was also unpopular there on election day, but still won it handily. The exit poll on election day had him underwater on favorability in plenty of states that he won easily, like IN, MO, and SC. He still won them.
The next Demodratic candidate is unlikely to be as unpopular as Clinton.
Sure, fine, but BRTD said that Trump is unpopular *now* in Iowa, as if this is some new development. No, Trump was unpopular on election day (both in Iowa and nationally) and he's unpopular now. I haven't seen anything to suggest that he's any less popular now either in Iowa or nationally than he was on election day.
Or, to put it another way, if Trump maintains his current unfavorability until election day 2020, and he's running against someone with ~even favorability #s, then sure, he's in trouble in Iowa. But he's also in trouble in so many other states that he's losing badly nationally, and it doesn't really matter what happens at the state-by-state level.