It felt, with apologies to Yogi Berra, like “déjà vu all over again.”

In July, after all, it will be 15 years since a skinny guy with an odd name sang a hymn to American union. “There is not a liberal America and a conservative America,” then-Illinois state Sen. Barack Obama told the Democratic National Convention. “There is the United States of America. There is not a black America and a white America and Latino America and Asian America – there’s the United States of America.”

Last week, another skinny guy with an odd name – Beto O’Rourke – sounded a similar theme as he kicked off his presidential campaign in El Paso. “Whatever our differences,” declared the former congressman, “where you live, who you love, to whom you pray, for whom you voted in the last election – let those differences not define us or divide us at this moment. Before we are anything else, we are Americans first.”

He surely didn’t intend it, but his evocation of that theme only pointed out how drastically the nation has changed since Obama evoked it in 2004. Back then, it played as a necessary corrective to an era of political polarization, an inspiring reminder of shared values and common heritage. Fifteen years later, it just sounds like wishful thinking.

Former Texas congressman and presidential candidate Beto O’Rourke Associated Press/Charlie Neibergall

Which says less about O’Rourke than about the country he aspires to lead.

The notion of one nation, indivisible, once seemed a bracing and defining ideal, the bedrock to which we could always return. But succeeding years have shaken that bedrock until what was once bracing and defining now feels like a sugarplum fairy tale, with no bearing upon the hard reality of us, here and now. Worse, it feels like a denial of the present state of our Union, of how deeply cracked is the foundation of this house.

The division is only nominally political. To the contrary, it encompasses geography, education, class, religion, culture, sexuality and, most of all, race. Yes, it is exacerbated by politics and yes, politics – specifically, the gleeful, playing-with-matches-in-dry-tinder opportunism of the Republican president and his apologists – has frequently been its proxy.

But ultimately, this division is about the simple fact that increasingly, we don’t like us.

Think of the white man who went on a bizarre rant last week because he saw a Spanish word on the menu of a Mexican restaurant in California.

Think of political leaders at every level peddling Islamophobia and racism. Think of white supremacists with Tiki torches parading in a public park.

Think of the shootings at a synagogue in Pittsburgh and a gay nightclub in Orlando. Think of the bombs sent to a cable news network and progressive politicians.

And think of how hate crimes have spiked, how bullhorns have replaced dog whistles, how bigotry has been called in from the margins and given a berth on prime-time cable.

Into that fraught moment steps O’Rourke, invoking the secular faith of a nation comprising other nations and bound by a stated belief in human equality. “Before we are anything else,” he says, “we are Americans first.”

It stirs memories of a day before acrimony became permanent. You want to believe it because what else are you going to do? To not believe it is to make the country a failure and a lie. So you hope maybe he sees something you can’t yet see. Or that maybe stubborn faith can make the thing true.

Right now, all that can be said for sure is that, last week, another skinny guy with a funny name told us we are one nation, indivisible. And maybe we are.

But that used to be a whole lot easier to believe.

Leonard Pitts Jr. is a columnist for The Miami Herald. He can be contacted at:

lpitts@miamiherald.com