At her first rally with Tim Walz, Kamala Harris delivered a riff about their quintessentially American backgrounds. She grew up in Oakland, Calif., raised by a working mother, while he grew up on the Nebraska plains, she explained. They were “two middle-class kids,” she said, now trying to make it to the White House together.

“Only in America,” Harris said, as the Philadelphia crowd burst into a chant of “U.S.A.! U.S.A.!”

This sort of unabashed patriotism doesn’t always come naturally to today’s Democratic Party. But it has been central to Harris’s presidential campaign. In her ads and speeches, she portrays herself as a tough, populist, progressive patriot.

It has made a difference, too. Harris has persuaded — for now, at least — a meaningful slice of swing voters that she is not the out-of-touch California liberal who Republicans claim she is. In Michigan, Pennsylvania and Wisconsin, she has surged ahead of Donald Trump partly because she is performing better with working-class voters and rural voters than President Biden was (even before his disastrous debate), according to Times/Siena College polls. Across both the Midwest and Sun Belt swing states, she is faring better with independents.

Today is my first newsletter after an August break, and I am struck by how much Harris’s message has revolved around progressive patriotism over the past couple weeks. With the Democratic convention about to begin, I’ll explain why you can expect to hear more of this theme from Harris and Walz.

I know that many Democrats already consider their party to be the patriotic one. Republican protesters, after all, were the ones who violently attacked Congress in 2021, and Donald Trump regularly portrays modern America as a hellscape.

But it also the case that Republicans are more comfortable with many expressions of patriotism than Democrats are. Republican voters are much more likely to describe themselves as “very patriotic” than Democratic voters are, according to YouGov polls. And Republicans are more likely than Democrats — especially highly educated Democrats — to say that the United States is the world’s greatest country: