DNC joy over Kamala Harris, Donald Trump’s sinking polls: Joe Biden made it all happen.

If you liked what you saw on the first night of the Democratic National Convention, you can thank Joe Biden.

If you’re enjoying seeing Donald Trump’s reelection campaign flail and spiral, you can thank Joe Biden.

And if you’re digging the Democrats' joyful message and newfound enthusiasm … well, you know.

None of what’s happening now in the presidential race would be happening without Biden stepping aside and supporting Vice President Kamala Harris’ ascension to the top of the Democratic ticket.

The transformation of the presidential race began with Joe Biden

Harris and her team have done a remarkable job launching her presidential campaign and swinging the polls in her direction. Trump and the Republican Party have done a spectacularly bad job responding. But it all started with what is arguably one of the most selfless decisions in American political history.

That decision was loudly celebrated and appreciated Monday night at the United Center in Chicago, as a packed house cheered Biden on and lauded his years of public service.

Harris made a surprise appearance early in the evening, saying: "I want to kick us off by celebrating our incredible president, Joe Biden. ... Thank you for your historic leadership, for your lifetime of service to our nation, and for all you will continue to do. We are forever grateful to you.”

Cheers of 'Thank you, Joe!' filled the DNC arena

Later, former Secretary of State Hillary Clinton said: “Let’s salute President Biden. He has been democracy’s champion at home and abroad. He brought dignity, decency and competence back to the White House. And he showed what it means to be a true patriot. Thank you, Joe Biden, for your lifetime of service and leadership.”

Thousands launched into chants of “Thank you, Joe!”

Blame Trump and MAGA. Republicans, are you still confused by Harris' momentum?

Biden’s critics, undoubtedly, will pooh-pooh Biden Appreciation Night. They’ll claim he was forced out. Trump will say it’s unfair. He’ll repeat his bizarre and astonishingly wrong claim that it was “a coup.”

That’s all fine. That’s their thing. Monday night wasn't for them.

And I’m not going to sit here and claim Biden swiftly and humbly stepped aside when he saw the Democratic base unenthused about his reelection bid. It took a bad debate, one that, fair or not, highlighted his age and flattened his chances of winning. It took pressure from congressional Democrats, pundits and even celebrities.

A politician deciding to let go of power is rare, and Biden deserves praise

But the “how” of it all is a lot less important than the end result.

A man holding the highest office in the land listened, saw the writing on the wall and decided to get out of the way for the good of his party and, I’d argue, the good of the country.

The need for the DNC protests: The DNC protests in support of Palestinians need to happen. Why isn't that obvious?

That doesn’t happen much. People don’t often let go of power, as Trump himself has so loathsomely demonstrated since the moment he lost the 2020 presidential election.

But Biden did. And that set in motion a remarkable transformation of the 2024 presidential race.

With Biden at the top of the ticket, this would've been a very different DNC

It’s hard to envision what the DNC would have looked like had Biden not stepped aside. The Democratic mood post-debate was dour. The effort to compensate for what many saw as Biden’s age-related downsides would’ve overwhelmed this week. Democrats would have been walking on eggshells.

Instead, because of one decision, there was a bounce in their steps on Monday. There was an inescapable air of enthusiasm and a message of positivity and optimism.

When Biden took the stage to make the baton passing fully official, the crowd erupted, waving “We Love Joe” signs and cheering for minutes on end.

As he waved to silence the crowd, the old man who, one way or another, found the guts to loosen his grasp on power said this: “America, I love you!”

I happen to believe that’s true.

Follow USA TODAY columnist Rex Huppke on X, formerly Twitter, @RexHuppke and Facebook facebook.com/RexIsAJerk

You can read diverse opinions from our USA TODAY columnists and other writers on the Opinion front page, on X, formerly Twitter, @usatodayopinion and in our Opinion newsletter.

This article originally appeared on USA TODAY: Joe Biden DNC appreciation night was earned. He changed the election.