The Des Moines Register poll is an outlier when it comes to the presidential race. On the other hand, the track record of its pollster is outstanding.
The Des Moines Register poll is less of an outlier in the Iowa Senate race. Ernst also leads in two of the four other most recent polls I know of. In fact, Insider Advantage’s survey puts her up by six points. Quinnipiac, which surveyed the most likely voters of any of the five polls, gives Ernst a two point lead.
An Ernst victory would go a long way towards enabling Republicans to keep control of the Senate. Couple it with a victory by Susan Collins, and there’s a good chance Republicans would retain control.
Speaking of Collins, she continues to trail in all four of the most recent surveys I’ve seen. However, the average margin for her opponent is only two points.
If all other Senate races go as generally projected (which is actually unlikely), an Ernst victory would mean the Dems control 50 seats, enough for an effective majority if Biden defeats Trump. Victories by Ernst and Collins would leave the Dems with only 49 seats.
Even with a 50 vote “majority,” Democrats would have to rely on Joe Manchin. It’s far from clear that he would back the most radical agenda items Biden and Chuck Schumer have in mind.