Trump leads the final Selzer poll of Iowa by 7 points, 48 to 41.
That's the same margin as their final poll four years ago, which wound up foreshadowing Trump's Midwestern sweep https://www.desmoinesregister.com/story/news/politics/iowa-poll/2020/10/31/election-2020-iowa-poll-president-donald-trump-leads-joe-biden/6061937002/

This is most certainly the president's best poll result in a very long time--perhaps of the whole cycle.
Biden campaigned there yesterday, so it's quite obvious that this isn't how they see the race here. But campaigns have been wrong before

It is also worth noting, though, that Selzer can be wrong, and has been before. No pollster has been put on a higher pedestal, but in the end everyone in this business is subject to sampling error and so on. If you expect perfection out of N=800 polls, you won't get it

And this Selzer Iowa poll is off on its own, not just in Iowa but in terms of the overall story. Every national poll has shown doing Biden way ahead of Clinton among white voters / white working class voters. He's excelled across the white, northern tier.