“Paul Ryan was correct when he did the tax code. What’s the first thing he decided we had to go after?” Biden continued, leaning into the microphone. “Social Security and Medicare … That’s the only way you can find room to pay for it.”

It was part of a broader speech in which Biden outlined his economic vision. He previewed his 2020 campaign emphasis on the middle-class but declared that billionaires are not “the problem,” an implicit contrast with progressives. The statement that Gunnels highlighted reflects a common Biden argument from the 2020 campaign: that Republicans pushed a tax cut whose benefits are tilted to corporations and the wealthiest Americans, knowing it would balloon the deficits, so the GOP could then justify cutting Social Security and Medicare.

“What I’d do is I make sure that we expand Social Security coverage,” Biden insisted Friday when a voter in Iowa asked him about the program.

Biden, like most Democrats, proposes raising the cap on the level of income that is subject to the payroll taxes for Social Security and Medicare. That cap is set at $137,700 for the current tax year, meaning any income beyond that threshold is still subject to personal income tax, but not payroll taxes. Biden —