Iowa polling is all over the farking place. I can't make heads or tails of any of it, other than Steve King's replacement being 20 points up on the Dem in NW Iowa.
Statewide, the R-D-I split is roughly 34-34-32, though Ds outnumber Rs in 3 of the four districts (again, Steve King's old district is heavily R).
Greenfield has generally been up 2-3 points on Ernst, but Trump has generally been 2-3 points up on Biden.
Axne (D) is up 5-10 points on David Young in a rematch of 2 years ago in the swingiest district in the state (Des Moines + SW Iowa). 2 years ago, Axne won Polk County (Des Moines and most suburbs) and lost everywhere else, but she limited the damage in Dallas County (Des Moines white flight).
Finkenauer (D) is up 10+ points on Hinson in NE Iowa, an area that went for Obama twice but then turned hard R for Trump (the district had one of the largest blue to red swings of any district in the country) before going blue 2 years ago.
In the one open seat, Miller-Meeks (R) is up 2-3 points on Hart (D) in SE Iowa notwithstanding Johnson County (Iowa City) and a 30,000 D registration advantage overall.
Redistricting next year will be interesting. They'll need to shift a net of about 50,000 people out of Axne's district, with most of it going to the NW Iowa district and a little to the SE district.