WI-Marquette Law: Biden +4, Sanders +1, Buttigieg -2, Warren -3

[LAKISYLVANIA]

If I had to guess, this is a state where the whole Iran situation is really hurting Trump. He has no one to blame but himself for trailing in what is obviously a must-win state for him.

If i had to guess, the Iran situation is actually helping him, and his approval rating is up since last poll. I wouldn't draw conclusions though from this poll. The last poll likely overestimated Trump. This seems more right, but it has a large difference between a +4 for Biden and a -3 for Warren.

[LAKISYLVANIA]

WI is lean R

Exactly for Warren and Buttigieg, but it's lean D for Biden and tilt D for Sanders.  And either Uncle Joe or Bernie is going to be the nominee.

It's lean R against all dems. He is within the MOE in all of these polls and polls notoriously undercount his support.

This is primarily due to improper weighting by the pollsters in 2016.  Do you think pollsters never learn or adjust their models?  For some pollsters this might be true, but not for the good ones (of which Marquette is certainly one).  Just because this happened in 2016 does not mean it's guaranteed to happen in 2020; you're making the same mistake that Democrats did by assuming that what was true in 2012 would also be true in 2016.

Nitpick all you want but you can't deny that things look much better for Trump in January 2020 than they did in January 2016.

And let's see how polling is by late October before we declare Wisconsin to be Lean D for Joe or Bernie, even if these Marquette numbers are accurate they will undoubtedly change over the course of the campaign. I also wouldn't be surprised to see a rerun of the 1968 disaster at Milwaukee this year!

Back in january 2016, there was still such a thing as #NeverTrump'ers, and the GOP wasn't united behind Trump. Now they are. That's the difference between the january poll from then and now. He wasn't the nominee yet, and the excellent pick of Pence wasn't made yet. Neither did Trump campaign in Wisconsin yet.