Pennsylvania, with its 20 electoral votes, was supposed to be the Blue-leaning state that could make or break Donald Trump’s bid for the White House.

The theory was that Trump would hold most or all of the states captured by Mitt Romney in 2012, add traditional battleground states Ohio and Florida, and then expand the map to capture the Keystone State, which Romney only lost by 5 points.

It may not happen that way. The former First Lady has opened up campaign offices all over the state, has outspent Trump on advertising by a huge margin, and enjoys the support of influential surrogates like former governor Ed Rendell. She’s also had President Obama and Vice President Biden stumping for her.

Biden, who hails from hard-scrabble Scranton, is thought to be a real asset when it comes to wooing the Keystone State’s disaffected coal miners and steel workers. With the polls tightening, he’s heading back to Pennsylvania this week and could end up camping out there until Election Day.

But Trump may not need Pennsylvania. With Hillary expending so much capital to try to turn that state into her firewall, the billionaire real estate mogul has been able to make steady inroads in a number of other Blue-leaning states where the GOP controls the statehouses and Hillary’s ground operation is weaker.

Of these, perhaps none is more critical than Wisconsin. Obama carried the state twice by a significant margin, and Clinton herself opened up a 15-point lead in early August in the wake of the Democratic convention. But the latest polls from Marquette University show the two candidates in a statistical dead heat.

Wisconsin is illustrative of the advantage that Trump has in states where the sitting governor is a Republican. In Virginia and Colorado, where Trump is seeking to keep competitive, he’s up against an entrenched Democratic Party control of the statehouse. And the demographics in those states are increasingly favoring Democratic voter groups, including Hispanics and moderate-to-liberal suburbanites.

Contrast that to the history of Wisconsin where seven of the last eight governors have been Republicans. In fact, the current two-term Republican governor, Scott Walker, who briefly ran for president earlier this year, is still a folk hero in his party for having beaten back a Democratic recall effort in 2012, just two years after he’d been elected. Democrats and their affiliated public sector labor union were appalled at Walker’s deep budget cuts including his campaign to roll back labor’s collective bargaining rights, but they severely miscalculated the feelings of Wisconsin voters, especially independents, many of whom thought Walker deserved a chance to demonstrate what he could accomplish.

But it’s not just Walker. Speaker of the House Paul Ryan, a seven-term congressman, is also a Wisconsin native son, and was Mitt Romney’s running mate in 2012. He’d been on the fence with Trump ever since the billionaire real estate mogul captured the nomination, but in early September he decided to weigh in behind the Trump campaign while backing GOP state candidates seeking congressional seats. Ryan’s quiet intervention is helping to counter the proposition that support for Trump can only hurt the GOP’s “down-ballot” candidates.

The fact is, Wisconsin voters, like those in nearby Ohio, where Trump has opened up a solid 5-point lead in recent polls, have good reason to respond to Trump’s message. Manufacturing is still the dominant economic sector, and though job losses have not been as severe as elsewhere, they have come at a steep price: severely depressed wages. And these job trends are clearly linked to free trade competition, especially from NAFTA, and to immigration, just as Trump has suggested.

A recent report on Wisconsin found that a whopping 40% of the state’s prized industry relies on immigrant labor, some of it legal, but much of it not. These workers don’t vote – but Wisconsin’s overwhelmingly white working population – much of it angry – does.

[dcquiz] Until recently, Trump was still underperforming in the Greater Milwaukee area, which Walker carried by nearly 50 points, and Romney carried by 30 points in 2012. In polls conducted through August, Trump was leading Clinton by just 13 points in this Republican bastion, with some 20% of voters, mainly Republicans, undecided.

But die-hard Republicans have begun consolidating behind him, according to the latest polls. And Trump’s visit to the Waukesha suburbs this week could well seal the deal.

The upshot? Clinton, in her rush to defend the Keystone State, inadvertently left a slew of Midwestern states vulnerable to encroachment by Trump. And encroach he has, clearing some fresh and unexpected paths to victory. Even were he to lose Pennsylvania, victories in Wisconsin, Iowa, and Nevada (22 electoral votes combined) could more than make up the difference.