Sen. Marco Rubio, a far-right Republican from Florida, has always benefited from an inspiring family history. Even his harshest critics have been willing to concede Rubio’s background, and the perseverance of his family battling long odds fleeing a repressive regime, is a great American story. It’s not at all surprising, then, that Rubio would shape his political identity around this story, making it the cornerstone of his 2010 stump speeches and campaign advertising.

There is, however, a problem. The story isn’t true.

During his rise to political prominence, Sen. Marco Rubio frequently repeated a compelling version of his family’s history that had special resonance in South Florida. He was the “son of exiles,” he told audiences, Cuban Americans forced off their beloved island after “a thug,” Fidel Castro, took power.

But a review of documents — including naturalization papers and other official records — reveals that the Florida Republican’s account embellishes the facts. The documents show that Rubio’s parents came to the United States and were admitted for permanent residence more than 2 1/2 years before Castro’s forces overthrew the Cuban government and took power on New Year’s Day 1959.

Even this morning, more than 12 hours after the Washington Post first broke the news that Rubio’s family history is not what he says it is, the senator’s office hasn’t bothered to correct his online biography. The second sentence, as I type, reads, “In 1971, Marco was born in Miami to Cuban-born parents who came to America following Fidel Castro’s takeover.”

Unless Rubio believes 1956 follows 1959, that’s plainly not true. To publish a falsehood is a problem. To leave the falsehood uncorrected after it’s been exposed is brazen.

For his part, the right-wing senator defended his bogus story by saying he’s “going off the oral history of my family.” Way to throw your parents under the bus, Marco. He’s not lying; he’s only wrong because those rotten family members misled him.

In this case, the problem with the truth is that it’s actually fairly mundane. Rubio’s parents, like millions of other Americans’ parents, simply chose to immigrate to the United States. They weren’t fleeing persecution or tyranny; they just wanted a better life. They became Americans and had a family.

There’s nothing wrong with this story, of course; it’s quite nice. But it’s also quite common and not the sort of thing a politician can exploit to inspire others.

So, the story changed and the fabricated version of events were infused with a larger political meaning that reality didn’t offer.

It’s hard to say, at least at this point, how damaging this will be to Rubio’s career — he’s assumed to be the top Republican choice for the vice presidential nomination, no matter who wins the GOP nod — but as a darling of the party, the media, and the political establishment, this certainly takes some of the bloom off the rose.

Postscript: These revelations came to light, by the way, following, of all things, a “birther” controversy launched online by those who questioned whether Marco Rubio is a natural-born citizen. He is, but the questions raised by the conspiracy theorists led to these other facts coming to public light.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.