SALENA ZITO: How Trump made small-town America matter again.

By the time he arrived in Pennsylvania in April, a state that had not seen a contentious Republican primary since the 1980 Ronald Reagan-George H.W. Bush contest, Trump had already annihilated 15 of his 17 Republican rivals.

And while no one was looking, 90,000 registered Democrats switched their affiliation to vote for him in the primary.

The only two left to battle against him in the Keystone State were Ohio Gov. John Kasich, who was born there, and Cruz, who had built up an army of pledged delegates in the state. Pennsylvania has a quirky delegate system: The winner is not who has the most votes, but who has the most pledged delegates, a process that requires a candidate to have deep establishment connections to the delegates and the willingness to win them over.

Cruz had plenty of that and Kasich was trying, but Trump was about to show everyone he knew how to connect when needed. *

The drive from Pittsburgh to Harrisburg on old US Route 22 to see Trump’s first rally took an hour longer than on the Pennsylvania Turnpike, but the trip began to tell the story of how this candidate would most definitely be the Republican nominee, and possibly the president.

Town after town was worn down by neglect. Main Street shopping districts were half boarded up, sometimes with only a Dollar General store serving as an anchor. Voters were angry with Washington, DC, disappointed in President Obama, and were tired that every time they sent DC a message with their votes, elected officials misread it. . . .

As with Trump’s visits to Minnesota, Michigan and Wisconsin, experts chuckled at the waste of time and effort in states they believed he would never win. But the campaign believed there were plenty of Trump-Pence voters hiding in plain sight.

In the end, he pulled off a stunning win in Pennsylvania, turning out voters in counties like Luzerne, Erie, Cambria, Washington and Westmoreland at a rate that eventually would offset Hillary Clinton’s solid numbers in Philadelphia and Pittsburgh.

The key was picking off Obama Democrats in the suburbs and rural areas, and getting regular Republican midterm voters, but squeamish presidential voters, energized. It worked. Just as it worked in Wisconsin, Michigan, Ohio, Florida and North Carolina.

Trump’s win was threefold. It occurred during populist unrest; he was unlike anyone whom voters had ever seen before; and the experts misjudged how disliked Obama’s policies were, because the focus was too much on his personal popularity.

Data were never able to track that type of emotional push against government.

One way to look at this election is via Tyler Cowen’s suggestion that in America, presidential elections are as much about various groups rising or falling in status as about policy. This perhaps explains the status anxiety behind so much Trump Derangement.