Marco Rubio felt out of place for a moment.

On the cusp of being sworn in as Florida’s newest senator in 2011, the Miami-born son of Cuban exiles had wandered away from his family during a tour of George Washington’s Mount Vernon home.

“I watched them from afar for a minute, laughing and talking in Spanish and English,” Rubio writes in his new book, An American Son.

“My first thought was how different my family was, how different I was, from the men and women who had lived in this place, and from the Americans who had founded our nation,” he writes.

“We looked and sounded different from the descendants of George Washington’s generation,” he continues. “But we embodied everything America’s founding generation had hoped America would become.”

That contradictory sense — of otherness but connectedness — is central to the immigrant experience in America. And it’s a key to understanding Rubio, whose book dropped just as his name began rising on the shortlist of potential running mates for Republican presidential candidate Mitt Romney.

In 303 breezily written pages, the outgoing cocksure Rubio sometimes comes across as shy and plagued at times by doubt. He dwells on the spiritual yet seems to obsess about money, which was always tight. For a politician so apt to talk about the future, he seems equally bound to the past.

A lawyer, Rubio first won political office 14 years ago.

Rubio’s conservative worldview was shaped by being both the child of immigrants and a member of Miami’s Cuban exile community, which treats him like everyone’s collective son. When Rubio served in the Florida House, he often downplayed the fact that he was the state’s first Cuban-American House speaker, serving from 2007-2009. Now he celebrates that past. ”

“I often feel as if I live in two worlds,” Rubio, 41, writes at one point, summing up the sentiment of anyone who lives in Miami-Dade. “I am the son of exiles.”

So he’s not just An American Son, which reads like two books in one.

It’s an autobiographical story of the son of hardworking immigrants who toiled as a bartender and a maid. But this is also a political document, an insider’s account of Florida politics.

Rubio gets the chance to control his own story, which has been the focus of intense scrutiny after he exploded on the national political scene. Rubio explains away many of the critical stories about him and his record as the result of “leaks” from his opponents (not all were) and as largely unfair or inaccurate (they weren’t).

Chock full of behind-the-campaign-scenes tidbits and political musings, Rubio’s narrative dwells most heavily on his nationally watched campaign for U.S. Senate against former governor and former fellow Republican Charlie Crist.

Rubio confesses he almost dropped out of the race against the once-wildly popular governor. His wife, Jeannette, helped persuaded him to stay and beat Crist. Rubio stuck with it, he writes, because he felt the governor was a rabble-rousing opportunist whose populism was bad for the GOP and the state.

Rubio also stayed in the race after Crist allies prematurely told reporters that Rubio would leave the campaign. That backfired. Had they paid attention to how Rubio, as speaker, fought Crist during a 2007 feud over property taxes, they would have remembered that he’s far too stubborn and too proud to get pushed around by Crist.