For those spinning visions of San Antonio Mayor Julian Castro as the Democratic presidential nominee in 2016, the 37-year-old has this to say: Not so fast.

Castro, who made history by being the first Latino to deliver the keynote address for the Democratic National Convention, says he plans to be Mayor Castro for many, many years to come – even if there is now a #juliancastro2016 Twitter hashtag.

“I’m flattered,” he said of the hashtag and the all that it implies, “But that’s never going to happen.”

“I’m the mayor of a city,” he told Fox News Latino in an exclusive interview at the Democratic National Convention in Charlotte, North Carolina. “I want to be in San Antonio to make it an even greater city, if the voters will have me.”

Castro said he did not depart from his written keynote speech, but one of the high points of the convention for him was listening to someone who did – often and at great length – former President Bill Clinton.

Clinton made numerous detours from his speech, and spoke nearly twice as long as he’d been scheduled. He ended up getting rave reviews, from longtime fans and political foes alike.

“Getting to hear the First Lady, getting to hear President Clinton, and having their words resonate with the American people, that was very moving [for me]. They did a great job.”

Castro laughed when asked if he and his identical twin, Joaquin, a political success story in his own right, step in for each other and try to get by at times getting people to think one is the other.

Joaquin, who accompanied his brother to the convention and introduced him Tuesday night before he gave his much-anticipated keynote address, was frequently stopped by delegates and politicians and journalists who mistook him for his brother.

Julian Castro admitted to having played the twin-switching game in high school, but not in general.

He said the wedding ring gives the brothers away.

“He’s not married yet,” he said. “[Joaquin] also says that I’m not quite good looking enough to impersonate him.”

And what about American’s new sweetheart, his 3-year-old daughter, Carina? Before millions of transfixed viewers, the toddler famously twirled strands of her hair and looked this way and that as her father delivered the speech of his life (so far).

“Going into the speech, [Carina] knew that her dad was going to make a big speech,” Castro said, “and she stole the show in the end.”

But someday Castro hopes that the little girl who found the loopy convention hats and glittery outfits and bright lights and huge arena at many moments more attention-grabbing than her daddy will understand and feel proud of that historic moment.

“My hope is that when she’s a little bit older, she’s only 3 now, she’ll really appreciate the moment when she was with her family [in an important national event] and that she stole the spotlight.”

Finally, Castro had words of advice to young Latinos.

“Keep working hard. . .their dreams will come true if they work hard,” he said. They must keep in mind “that the America we live in in 2012 is an America where all of our founding documents mean the same thing for them [as for other Americans].”

“Just as I was able to achieve my dreams,” said the son of a civil rights activist, who raised her children as a single mother, and saw him and his brother go on to Ivy League schools, “if they work hard and they want to be an astronaut or they want to be a doctor or a teacher, they can achieve that.”

Elizabeth Llorente can be reached at elizabeth.llorente@foxnewslatino.com

Follow Elizabeth Llorente on https://twitter.com/Liz_Llorente

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