According to the polls, Donald Trump has been trailing Hillary Clinton badly in Michigan and Wisconsin for months. In Michigan, two surveys taken last week showed Clinton leading by seven percentage points. In a third poll, the margin was six points. It's a similar story in Wisconsin, where the past three polls have shown Clinton ahead by four points, six points, and seven points.

Why, then, with just more than a week left before Election Day, is Trump campaigning in these two states? Surely he would be better off camping out in places where the polls are closer, such as Florida, Nevada, North Carolina, and Ohio—that's what many Republican strategists believe.

The Trump campaign, though, is operating according to its own logic, or illogic. A few weeks ago, the Wall Street Journal reported that the campaign believed that its best chance of victory was to eschew the middle ground, seek to create a bigger-than-expected turnout among Trump's core demographic, and bank on Democratic turnout being low.

The first part of this proposition, at least, is based on some actual electoral arithmetic. Trump's core demographic is white working-class voters, many of whom react positively to his populist and nativist message. In a Fox News survey carried out last week, Trump was leading Clinton by twenty-eight percentage points among whites without college degrees. The big challenge facing the Republican candidate is that, in recent elections, as many as half of all white working-class voters haven't voted at all. But that, conceivably, is also an opportunity. If these voters could be persuaded to show up at the polls in large numbers—much larger than the pollsters are expecting—it could make a big difference, especially in places where there are a lot of them.

Where are these places?

Last year, David Wasserman, of the Cook Political Report, broke down the demographics of the 2016 electorate in fifteen potential battleground states. In eight of these states, Wasserman calculated, the proportion of non-college-educated white voters would be thirty-five per cent or more: Arizona, Iowa, Michigan, Minnesota, Missouri, New Hampshire, Ohio, and Wisconsin. In the other seven battleground states, the proportion of white working-class voters would be less than thirty-five per cent.

That divide helps explain why Trump, according to the polls, is ahead of Clinton in Iowa, Missouri, and Ohio. It doesn't account for Trump's relatively weak showing in Michigan, Minnesota, and Wisconsin—three states that are home to lots of working-class whites. Earlier this year, the Trump campaign was hoping to incorporate the Upper Midwest into a "Rust Belt strategy," believing that the region, which has lost a lot of manufacturing jobs to foreign competition, would respond well to his protectionist message. Michigan, in particular, seemed like a potentially ripe target: virtually half of the voting-age population there is composed of whites without a college degree, according to the Census Bureau. But things didn't work out.

Perhaps that shouldn't be surprising. At the Presidential level, these are solidly Democratic states. In all ten elections since 1976, Minnesota has voted Democratic. Wisconsin has been a solidly blue state since 1988, Michigan since 1992. Why should this year be different? In the Upper Midwest, at least, the white working class is far from monolithic. Many working-class whites still associate with trade unions and the Democratic Party. In addition, Michigan and Wisconsin are both also home to large numbers of college-educated whites, a group that, on a national basis, appears to be backing Clinton.

Trump doesn't have many options, though. As yet, his recent rise in the polls hasn't affected the outlook for the Electoral College much. Even if he won Florida, Ohio, and North Carolina, and carried all the other Republican-leading states—including Arizona and Utah—it wouldn't be enough to bring him to victory unless he also picked up at least one sizable blue state. Until now, he has focussed much of his attention on Pennsylvania and Nevada. But things aren't looking good for him in either of those places. On Monday, Jon Ralston, an acknowledged expert on Nevada politics, said that Clinton is so far ahead in the early voting that it will be extremely difficult for Trump to catch her. Meanwhile, the last time a reputable poll showed Trump leading in Pennsylvania was in July.

Hence the Trump campaign's last-minute effort to expand the electoral map to the Upper Midwest. Asked why Trump scheduled two events in Michigan for Monday, a senior adviser to his campaign told the Detroit News: “Our numbers show this race being a dead heat with Hillary really hitting a ceiling in the state.” That sounded like boosterism. But Trump and his coterie aren't visiting Grand Rapids, Warren, and Eau Claire just for the fun of it. They are trying to rally their own.