Delaware County, a longtime Republican stronghold until just a few years ago, boasts just 49% registered Democratic voters but sent Biden some 62% of the vote. Montgomery’s 50% registered Democrats is a fraction of the 63% vote share that Biden won.

Now you understand why I so badly wanted that karaoke mic in Center City.

This suburban blitz was an astounding display of getting-out-the-vote for Biden.

Even former Delaware County Democratic Party chair David Landau, a veteran of fighting losing battles, could not believe the numbers when I tracked him down Friday morning. Biden was ahead by an 81,700-vote margin and it was growing still.

“That blows away every presidential election I’ve been in. It’s historic,” said Landau, who until his departure as party chief a few years ago had worked for decades trying in vain to elect Democrats in the legendarily strong Republican stronghold. He left after the county began to flip into liberal hands.

Across Delco’s shared border into Montgomery County, Democratic Party head Joe Foster was just as impressed by Biden’s performance, though he was smarting over big Democratic losses in state legislative contests where many Biden voters inexplicably picked Republicans for down-ballot races.

“We had at least 84% turnout,” Foster said, compared with the 77% that had made Montgomery County a standout in Clinton’s failed Pennsylvania bid in 2016.

The fact of “313,000 votes for Biden in Montgomery County alone” — compared with 256,000 for Clinton four years earlier — is extraordinary, he agreed. “We’ve never had those kinds of numbers before.”

In Delco, 199,618 voters chose Biden, compared with 177,402 for Clinton.

Trump, who drew even bigger vote counts in deeply Republican counties far from Southeastern Pennsylvania than he had against Clinton, squeezed barely 20,000 new votes out of Montco and a measly 5,000 from Delco.

On Saturday, major television networks declared Biden had won Pennsylvania and, with it, the White House. He’d done so with the Electoral College edge and a historic popular-vote lead over Trump. Legal challenges mounted by a president who spent the week comparing vote counting to fraud made it unclear if or when Trump would concede.

Given the penchant for infighting within their party, Democrats should take this time to find their better angels. They should avoid trying to pit one stakeholder group against another, given how Biden has reached victory.

Biden won Pennsylvania because all of his backers in this state came together with single-minded determination to make him president. Like pieces of a wooden Jenga toy tower, each one will have been critical to reaching the top.