Mayor Peter “Pete” Buttigieg’s speech throwing his hat into the ring for president strikes us as the best debut from a Democrat since 2004. That’s when the party’s nominee was introduced at Boston by a young senator named Barack Obama, who stressed the idea of a UNITED States of America. Mr. Buttigieg captured at his launch this evening a youthful optimism that, other than Mr. Obama, our country hasn’t heard from a Democrat since JFK.

Not that we’re unmindful of what happened in respect of the nominee in 2004. Senator Kerry boasted of heroism in a Vietnam war he’d betrayed. He was called out by veterans of the shallow water inland fast tactical vessels known as Swiftboats, which had carried the war to the communists infesting the Mekong Delta. His fellow Swiftvets deemed him “unfit for command” and sank his campaign.

Mr. Obama, though, ended up winning the presidency four years later. He had a thinner resume than that of Mr. Buttigieg, who appeared in arms in Afghanistan and has been six years a mayor. Mr. Obama, though, ran a refreshing campaign, handily dispatching an angry candidate in Senator McCain, only to fail at finding policies as unifying as his early speeches. He set the stage for President Trump.

One big difference between Messrs. Buttigieg and Obama is timing. Mr. Kerry’s ill-fated campaign gave Mr. Obama four years in which to hone his national standing and develop his narrative. Mayor Buttigieg doesn’t have that window. So his launch speech this evening was short on substance. It was, though, long on unifying and, at times, uplifting themes that we suspect are going to resonate widely.

That’s no doubt partly because for millions of Americans, the prospect of elevating to the White House the first gay president evokes genuine excitement. Just as the prospect of the first African American president put some well-earned wind in Mr. Obama’s sails. If the past is a guide, though, at some point the exigencies of policy are going to trump — pardon us — that kind of excitement, however worthy.

This isn’t an endorsement; the Sun is several kiloparsecs to the right of Mr. Buttigieg, even while we see a lot to admire in him (and enjoyed his book). Plus, we’ve been watching with dismay the way National Candidate Buttigieg has turned on his fellow Hoosier, Vice President Pence. The two had, by Mr. Buttigieg’s own account, a fine working relationship when Mr. Pence was governor of Indiana.

Yet lately, Mr. Buttigieg has been suggesting that Mr. Pence’s religious scruples make him a bigot. Mr. Buttigieg failed to speak up even for the vice president’s wife, Karen, when protests erupted at news that she would be teaching at a Christian school in Virginia. It is disappointing that Mr. Buttigieg couldn’t find it within himself to defend the free exercise rights of fundamentalist Christians and, thereby, other fervently religious Americans.

This evening Mr. Buttigieg sounded an off-note on the Electoral College, which, it turns out, he opposes. He wants to elect our presidents by popular vote. That’s a note of doubt that Democrats are going to be able to elect future presidents by the same system that handed up such leaders as George Washington, Abraham Lincoln, or Franklin Delano Roosevelt, to name but several of the greats.

In any event, the race is young. One thing Mr. Buttigieg has that Secretary Clinton lacked is bona fides with the Rust Belt. Whether they will prove to be a match for Mr. Trump’s full employment and record jobs for African Americans and other minorities, well, we will see. After this evening, though, it’s not difficult to imagine that Mr. Buttigieg can make the Democrats’ case in fresher fashion than, say, Senator Sanders or Vice President Biden.