Newsweek - Who Is Ann Selzer?
Selzer has been doing polls in Iowa (for the Des Moines Register) since 1987 - she's not a fly-by-night pollster (nor is Emerson, for that matter). She did predict Trump wins in Iowa for both 2016 and 2020. She was only off by 1 percentage point last time around.
That said, Iowa has the same number of electoral votes as Nevada; I still believe 538 has Trump with a very narrow edge in Nevada. Should Trump flip Nevada, it would be negated if Harris ends up flipping Iowa.