No one poll should be taken too seriously.
However, the fact that OVERWHELMING majority of polls taken in this particular race since September show Ernst leading Braley I think is probably an accurate reading.
Further, the Des Moines Register is the largest newspaper in IA and endorsed Braley, so there is no reason to believe that it would put out a skewered poll.
I don’t make predictions anymore, but I would truly be surprised if Joni loses tomorrow night.
You also have to look at the polls in the context of how the campaigns are acting.
Particularly right now, as GOTV mechanisms are spun up to drive and track turnout.
Campaigns will have turnout goals for each stage in the voting (early, absentee, election day), with mechanisms to track whether those goals are being met and provide short-turnaound (sometimes even realtime) feedback so the campaigns can try to implement corrective action.
Right now it seems like the Republicans are determined and confident, while the Dems are panicking. The GOP may just be clueless/oblivious (as they were with Romney in 2012), but there’s not a good reason for some of the things the Dems are doing other than they are seeing themselves already falling short of not only their goals but also their minimums.
So I’m cautiously optimistic about tomorrow.
The race will be called early for Lt Colonel Ernst. She will be a great addition to the US Senate and is a staunch conservative. Her husband is an Army full colonel.