ROBERT SIEGEL, HOST:
Throughout the Republican presidential primary season, whenever there's talk of possible running mates, one name is nearly always at the top of that list.
UNIDENTIFIED INTERVIEWER: Would you consider Marco Rubio as a running mate?
NEWT GINGRICH: Of course. I mean, he's going to be on everybody's short list.
SIEGEL: Newt Gingrich there, extolling the virtues of Marco Rubio, the first-term senator from Florida. He's a young, charismatic and conservative Hispanic. As his national profile has risen, Marco Rubio has become a target for Democrats and advocacy groups who say he does not represent Latino voters. NPR's Greg Allen tell us more.
GREG ALLEN, BYLINE: In Miami, a dozen young Hispanic men and women gathered outside Senator Rubio's office last week to send a message.
(SOUNDBITE OF PROTEST)
UNIDENTIFIED GROUP: (Chanting) Rubio: Latino or Tea Partino? Rubio: Latino or Tea Partino?
ALLEN: Helping lead the chants was Esteban Roncancio. He's 20 years old, studying computer engineering at Miami Dade College, and an undocumented immigrant. He's a prime candidate for the DREAM Act, a bill that would give students, and members of the military, who are here illegally a path to legal U.S. residency.
In surveys conducted by the Pew Hispanic Center, it's supported by over 90 percent of U.S. Hispanics. Rubio opposes it. Roncancio says that shows he's out of step with his community.
ESTEBAN RONCANCIO: He doesn't represent us and he - especially among young Latinos, we don't feel that we're similar to him. We want him to really be with his people, with his community instead of with Tea Party, anti-Latino policies.
ALLEN: Roncancio is part of Presente Action, a Latino advocacy group that has targeted Rubio with its No Somos Rubios campaign: We are not Rubios. Members of the group disrupted a speech Rubio gave in January to the Republican-leaning Hispanic Leadership Network. Rubio praised them for their courage in speaking out on an important issue, but made light of the campaign.
(SOUNDBITE OF SPEECH)
SEN. MARCO RUBIO: On my way in today, I got a text from a friend who said that someone is flying a plane over the building with a banner that says, Marco, No Somos Rubio.
(SOUNDBITE OF LAUGHTER)
RUBIO: Which means, Marco, we're not blonde - which by coincidence, neither am I. So...
(SOUNDBITE OF LAUGHTER)
ALLEN: In Spanish, Rubio means blonde.
As the only Hispanic Republican in the U.S. Senate, Rubio has tried to stake out a nuanced - some would say inconsistent - position on immigration issues. In recent weeks, he scolded Republicans for using harsh rhetoric on immigration. But he's also said he respects Arizona's right to impose tough restrictions on immigrants - restrictions that are opposed by a large majority of Latinos.
Rubio says he opposes the DREAM Act because it would set up a mechanism that he believes would encourage more illegal immigration. But he says something should be done for the young people the DREAM Act would help.
RUBIO: For those children that were brought here at a very young age by their parents, through no fault of their own; who have grown up here their entire lives and now want to serve in the military or are high academic achievers and want to go to school and contribute to America's future; I think there is broad bipartisan support for the notion that we should somehow figure out a way to accommodate them.
ALLEN: Although he's been in Congress for just over a year, Rubio's national name recognition has risen because of the vice presidential talk - talk he dismisses, saying he's focused on his job as Florida senator. But Rubio's rising national profile has helped make him a target of attacks from the White House.
Most recently, he took heat from the administration for backing an amendment introduced by Missouri Republican Senator Roy Blunt, that would allow religious groups to opt out of providing birth control coverage. The White House labeled it the Blunt-Rubio amendment even though Rubio was one of just 23 co-sponsors.
Last week, Illinois Democratic congressman Luis Gutierrez joined the criticism. In a call organized by Presente Action, Gutierrez accused Rubio of tailoring his message depending on whom he's talking to.
REP. LUIS GUTIERREZ: Lately, he's been going to the Latino microphones of America and saying well, I'm telling my colleagues in the Republican Party that they should not be so harsh with their rhetoric.
But then he says something to a different audience, including his Tea Party base.
ALLEN: Rubio's office says they're not surprised by the attacks; what they see as a concerted effort in a campaign year to undermine a popular Republican senator. Rubio has kept a low media profile recently. He's working on an autobiography. He released a few potentially controversial tidbits lately - such as that as a child, he was baptized and raised Mormon before embracing Catholicism.
Gabriel Sanchez, an associate professor of political science at the University of New Mexico, says if Rubio is on the ticket, it's not clear how much he'll do to help Republicans win over Hispanics. A survey conducted in November found more than a third of Hispanics had never heard of him.
GABRIEL SANCHEZ: I mean, he's very well-known, obviously, among folks close to Florida and among the Cuban-American population. But Mexican-Americans in the Southwest, they probably, you know, don't know much about him. And it's going to take some time for them to even understand, you know, who he is, what his issues are.
ALLEN: And that's where Democrats and immigrant advocacy groups come in, helping define who Rubio is as Latinos across the country are just getting to know him.
Greg Allen, NPR News, Miami.