Trump’s path to winning the general election is so narrow as to be invisible:

If Mrs. Clinton carries those states and wins Pennsylvania, she could withstand losses in Florida, Ohio, North Carolina and many other swing states—assuming she holds the traditionally Democratic states. She also likely would win with a victory in Ohio or Florida, even without the Keystone State, a sign of her strong position. But Pennsylvania, with its long history favoring Democrats, may offer her the easiest path forward.

“Pennsylvania is key to the entire race” as a must-win state for Mr. Trump, said Mitch Stewart, who was battleground states director for Mr. Obama’s 2012 re-election. For Mrs. Clinton, Pennsylvania likely would be the “tipping point’’—the state that puts a candidate over 270 electoral votes when states are listed in order of the winner’s most-likely victories, he said.

If Pennsylvania is a “must-win” state for Trump, Trump isn’t going to win the election. There is no reason to think that Trump will win Pennsylvania, nor is there much reason to think that any other Republican nominee would be able to do that. The state has voted for the Democratic candidate in every presidential election since 1992. Even when the Republicans won the popular vote in 2004, Pennsylvania still went for Kerry by two points. Obama carried the state by more than five points four years ago and won it by ten points in 2008. Clinton currently leads in the RCP average for Pennsylvania by more than nine in the two-way match-up and more than eight in a four-way contest. All that Clinton needs to do to win in November is to hang on to her lead in a state that has consistently voted for Democrats for president for over twenty years, and right now it appears she will be able to do that easily.