I explained here why I don’t think that 2018 will be a Democratic blowout along the lines that 2010, for example, was for Republicans. Today more evidence that November won’t be a walk in the park for Democrats came from Minnesota, where 8th District representative Rick Nolan announced that he will not seek re-election:

U.S. Rep. Rick Nolan said Friday that he will not run for re-election this year, an unexpected decision that elevates the stakes in what was already going to be an expensive, all-out battle between the DFL and Republicans for his northeastern Minnesota congressional seat.

The 8th used to be a Democratic Party bastion, but has been turning increasingly red. Nolan won the seat in 2012 and defended it narrowly in 2014 and 2016, both times against Republican Stewart Mills. Donald Trump carried the 8th District by something like 16 points, an indication of how strongly the tide is running against liberalism there.

Nolan had said as recently as last Summer that he would run for re-election. What changed? I can only assume that he was looking at some very bad poll numbers. His Republican challenger will be Pete Stauber, a strong candidate. Stauber is a long-time Duluth police officer who is now a St. Louis County Commissioner. St. Louis County is the chief DFL stronghold in the district, but Stauber has been running there successfully. I was confident that Stauber would beat Nolan; I am even more confident that he will beat whomever the Democrats nominate in Nolan’s place.

What is going on in northern Minnesota? A big part of the story is mining. Most people don’t realize it, but Minnesota is home to some of the world’s largest and most valuable mineral deposits. For twenty years or more, mining companies have been trying to develop mineral resources (mostly copper and nickel) valued in the hundreds of billions of dollars, if not trillions. But the Democratic Party has stalled them, at both the federal and state levels. The people of northern Minnesota have had enough.

The Republicans’ House majority is relatively slim, and the Democrats might well take control after November’s election. In that context, opportunities for GOP pickups are crucial. Minnesota has three of the last rural districts in the U.S. still controlled by Democrats–the 1st, 7th and 8th–and at least two, the 8th and 1st, probably will swing to the GOP this year. (Democrat Tim Walz, who currently represents the 1st District in southern Minnesota, is leaving Congress to run for governor.) Given the speed with which small-town America is turning red, the Republican nominee may defeat long-time representative Colin Peterson in the 7th, as well.

With two Senate seats up for grabs–a historic rarity–as well as the governorship, and five House races deemed competitive by the national handicappers, Minnesota will be ground zero in November.