Polling by Latino Decisions, an opinion research group Barreto co-founded, shows that a similar proportion of Latino voters view the GOP as hostile. And he said polls on Rubio showed no major support among Latinos outside of Florida.
Claros, the Salvadoran-Costa Rican, said many Central Americans feel overlooked in places where people of Mexican descent dominate. But despite rivalries and occasional resentments, he said he feels more of a kinship with Mexican Americans than he would with Cuban Americans, Puerto Ricans or other groups.
"They're East Coast Latinos. We're West Coast Latinos," Claros said. "If you're Central American, there's a disconnect with Cubans because you're not exposed to a lot of Cuban families or Cuban culture."
Rafael Fantauzzi, president of the National Puerto Rican Coalition in Washington, said he recalled when President Clinton considered nominating a Puerto Rican to the Supreme Court. Some Mexican Americans opposed it, thinking the nominee should be from the largest Latino group, he said.
No Latino was nominated that time. But when President Obama nominated Sonia Sotomayor to the high court three years ago, Fantauzzi said, Mexican American groups strongly supported her.
"The first Latino on the bench is a Puerto Rican from New York, and it never would have happened without our Mexican American brothers and sisters pushing the White House for that," said Ruben Diaz Jr., the Bronx borough president and a former New York state legislator.
Fantauzzi said some Latinos think Puerto Ricans don't care about issues like illegal immigration, being citizens by birth. That's not really true, he said, though for many Latinos, including Mexican Americans, the live-wire issue of illegal immigration isn't the top priority this election.
Still, Fantauzzi said choosing someone on a presidential ticket with a Spanish surname isn't necessarily a winning formula to get the Latino vote, he said.
"The idea that Marco Rubio would galvanize a large segment of the Hispanic vote purely because he's Hispanic is a fallacy," Fantauzzi said. "It's an insult to our intelligence that we would not really look at the value of a candidate and just look at his culture."