We just finished watching the Harris-Walz rally in Philadelphia. Do you want to know what Tracy and I took away? The political electricity of two candidates with great big wide smiles on their faces filled that arena with the theme of the night: “Thank you for bringing back the joy,” Governor Tim Walz said to Vice President Kamala Harris right after she introduced him.

The crowd went wild. Joy about the brand-new Democratic ticket was on everyone’s faces as they listened to Harris and Walz. It’s been quite a while since I’ve seen that kind of enthusiasm and delight in our politics. It’s hardly necessary to point this out, but I’m going to remind you anyway: at the grim rallies of Donald Trump, where he spreads lies about “American carnage” and blames everyone but himself, he never cracks a smile, and you don’t see smiles on the faces of his rally crowds. Trump paints a dark picture lamenting this country’s future, and his crowds lament right along with him.

Not tonight in Philadelphia. Democrats are smiling again, laughing at the jibes Harris threw at Trump for wanting to take people’s freedoms away and Walz’s patented refrain that Trump and Vance are just plain “creepy and weird.”

Energy in politics can’t be bought, and it can’t be manufactured. It has to just be there. Tonight, in an arena filled to its 12,000 capacity in Philadelphia, Kamala Harris and Tim Walz reminded Democrats who they are. Empathy is energy. Humor is energy. Dedication to freedom and justice is energy. Being willing to fight for what you believe is energy.

All around Vice President Harris as she spoke, people waved signs that read, “When we fight, WE WIN.” And they joined both candidates when they led the crowd in chanting the Harris-Walz campaign slogan: “We aren’t going back!” Walz captured the energy of the campaign when he said there are 91 days until the election. “This will be easy,” he said to cheers. “We’ll sleep when we’re dead.”

They are on a seven-state, five day swing through the battleground states billed as the campaign’s introduction of Tim Walz as the Vice President’s running mate. He’s not going to need much of an introduction when rally crowds see the smile on Kamala Harris as she holds his hand aloft. They say Walz has the folksy charm of the Midwest. Yes, but more than that, they both have the power of the smile that is renewing Democratic politics and energizing voters in Philadelphia in a way I haven’t seen in years.

Lucian K. Truscott IV, a graduate of West Point, has had a 50-year career as a journalist, novelist, and screenwriter. He has covered Watergate, the Stonewall riots, and wars in Lebanon, Iraq, and Afghanistan. He is also the author of five bestselling novels. You can subscribe to his daily columns at luciantruscott.substack.com and follow him on Twitter @LucianKTruscott and on Facebook at Lucian K. Truscott IV.