Once again, crowd size matters to Donald Trump.

On his first day as president in 2017, Trump started a public spat about something totally unimportant — claiming his inaugural crowd was bigger than Barack Obama’s in 2009.

“This was the largest audience ever to witness an inauguration,” said his press secretary, Sean Spicer.

It wasn’t.

Fast-forward to 2024 and not much has changed. Donald Trump is still fighting about crowd size.

This week Trump bizarrely claimed that ”NOBODY” was at Detroit’s airport to greet Vice President Kamala Harris at a rally — even though live television coverage showed thousands of people cheering the new Democratic Party ticket.

Trump went one step further, charging that Democrats were using artificial intelligence to make their crowds look bigger. It left Republicans in agony.

“Stop questioning the size of her crowds,” barked former U.S. House Speaker Kevin McCarthy.

“This campaign is not going to win talking about crowd size,” added Nikki Haley, who unsuccessfully challenged Trump in the GOP primary.

It’s nothing new for Trump. Last week, he claimed that he spoke to more people on Jan. 6, 2021, than were at the Rev. Martin Luther King Jr.’s 1963 “I Have a Dream” speech. The pictures show that’s not true either.

Democrats saw something more sinister, all related to Trump’s never-ending lies about election fraud in 2020.

“When he claims that ‘nobody’ showed up at a 10,000-person Harris rally,” said U.S. Sen. Bernie Sanders, I-Vermont, “he is laying the groundwork for rejecting the election results if he loses.”

If you just think about Trump’s obsession with crowd size and his false claims of election fraud, you can instantly understand why he has a problem growing his voter coalition. Neither one of those address the nation’s future or major issues confronting Americans.

Oddly enough, the politics of optimism, joy and hope — once locked securely in the GOP thanks to President Ronald Reagan — have now shifted to the Democrats.

The emergence of Harris has unleashed a sense of excitement among Democrats, independents and even some Republicans that wasn’t there for President Joe Biden.

The happiness at those Harris rallies couldn’t be a bigger contrast to the extreme anger that I hear so often from so many Republican voters — usually associated with anything related to Trump’s false claims about election fraud in 2020.

Fighting about crowd size and making odd claims about AI won’t create jobs. False claims about election fraud can’t fix the border.

But that’s what is on the mind of the Republican nominee for president. Still.

Jamie Dupree has covered national politics and Congress from Washington since the Reagan administration. His column appears weekly in The Atlanta Journal-Constitution. For more, check out his Capitol Hill newsletter at http://jamiedupree.substack.com.