Minnesota voters will send a message Tuesday, but what?

We're down to the wire and anyone who is honest will tell you they don't know what's going to happen Tuesday, because we don't really know what the universe of voters will look like.

Here are some keys to Nov. 6:

Married women barely favored Hillary Clinton over President Donald Trump in 2016. But there's evidence that support for Trump from suburban women, once a bulwark of the Republican coalition, has collapsed. As such, they want to put a check on Trump by electing a Democratic Congress. A late October poll by NPR/Marist showed that college-educated white women prefer Democrats by 18 percentage points in this year's congressional races.

How will we know if this is real? Watch the results in suburban legislative districts held by Republican women like Reps. Jenifer Loon, Sarah Anderson and Roz Peterson. They're experienced, they work hard and, well, they're women. If they're losing, what we're likely seeing is suburban women turning on Republicans.

Each party has its share of these. Democrats need minority and young voters to come out. With the exception of black women, they tend to skip midterm elections. This was fatal to Democrats around the country in 2014. The party hopes that anger about Trump will propel these voters to the polls.

Republicans have a similar problem with a key voting bloc: white working class voters who were never much engaged in politics until Trump. The party needs them this year, which is why Trump has been doing so many rallies in rural areas and highlighting immigration.

The realignment of Minnesota politics is nearly complete. While Democrats have made gains in the suburbs, support for the party has eroded in greater Minnesota. This trend has accelerated in starts and stops in the past eight years.

Trump won the First and Eighth Congressional Districts by more than 15 points, and the Seventh by more than 30. Republicans have the chance to flip all three of these congressional districts in greater Minnesota this year, which are all currently in Democratic hands.

But there's nuance. While both are in greater Minnesota, the First and the Eighth are vastly different in geography, culture, economy and demographics. Republicans look strong in the Eighth, which has been a Democratic stronghold for nearly a century. But the First is a tossup, and there's reason to think Democrats aren't dead yet in southern Minnesota.

Trump's trade moves pose risks for the agricultural economy, and the growing and diversifying city of Rochester provides Democrats a potential lifeline.

We'll know soon enough.

J. Patrick Coolican 651-925-5042 Twitter: @jpcoolican patrick.coolican@startribune.com