Obama immigration plan—enough to energize disaffected Latino voters?

President Barack Obama's decision to grant temporary legal status to as many as 800,000 young illegal immigrants was met with praise from Hispanic advocacy and civil rights organizations on Friday. The new rule "gives Latinos an added reason not only to support the president but to actually turn out and vote," said Brent Wilkes, the national executive director of the League of United Latin American Citizens. Obama's campaign must be hoping that this move will encourage Latinos—who have the lowest voter registration numbers of any major ethnic group in the United States, despite their growing demographic—to register and show up at the voting booth.

[Related: Six things to know about U.S. immigration]

The president enjoys a big lead over Mitt Romney among Latinos, but he faces two hurdles in translating that sentiment into electoral turnout. One, registered voters must be enthusiastic enough to actually show up on Election Day, especially in swing states, and two, new Latino voters—people who just became citizens or citizens who recently turned 18—must be registered to vote.

The challenges of the latter are particularly apparent in the battleground state of Florida, where a whopping 638,000 Latinos are eligible to vote but are unregistered, according to a recent report by the liberal think tank Center for American Progress. That's several times the number of votes by which Obama beat John McCain in the state four years ago. It could be enough to sway the presidential election—but only if you can convince Latinos to register.

Nelly Medina, a 62-year-old Miami resident who canvasses new voters as a volunteer for the National Council of La Raza, says that hasn't been easy.

"The people don't want to vote," she says in Spanish. "There's a lot of apathy. The two candidates that there are, they don't like either of them … [politicians] don't come through on their promises."

Medina has helped 1,000 new voters register over the past few months, but for every person who wants to vote, there's a handful who say they're not interested.

And get-out-the-vote leaders say their groups are more underfunded than in election years past, meaning there are fewer people like Medina trying to convince people to vote in the first place.

Clarissa Martinez, La Raza's director of civic engagement, said the group has had to halve its goal of registering 180,000 new Latino voters nationwide. In Florida, the group's efforts were slowed considerably by a new law that said registration forms had to be turned in within 48 hours of being completed. (At least one registration group dropped its efforts entirely because of the law, though a judge enjoined it several months later.) Ben Monterroso, director of Mi Familia Vota, said his group has reached only 30 percent of its voter registration goal in Florida, though it is doing better in Nevada and some other states. "The goals that we have need to be reduced because obviously without having the resources we need, we aren't going to be able to accomplish the goals," Monterroso said.

[Related: Romney won't commit to repealing Obama's immigration order]

"You have a perfect storm right now," Martinez says. Super PACs have flooded the airwaves with negative ads, which turn potential voters off, she says. "A lot of resources are going into negative ads, and at the end of the day the effect is to decrease participation, not increase participation." And new voters are not the only group that needs attention: The recession and foreclosure crisis have caused people to move around more than usual, meaning registration volunteers are also working to reregister existing voters, rather than focusing on signing up new voters.

"Part of the effort is to make sure we don't slide back. That we continue to add people to the rolls and that people who participated continue to participate," Martinez says.

The nonpartisan National Association of Latino Elected and Appointed Officials estimates that 12.2 million Latinos will vote in November, which would make them 8.7 percent of the electorate. But the growth in the number of Latino voters isn't quite keeping pace with their population growth, and voter participation remains low compared to other racial and ethnic groups in America. In 2008, only about half of Latino Americans voted, compared to about 65 percent of white and black Americans.

Sylvia Manzano, project director for the Latino Decisions polling organization, says she listened in on focus groups with unregistered Latino voters in Texas and California over the past year that shed light on why the rolls stubbornly refuse to budge. People in the focus groups were informed about the presidential candidates and their opinions, but said they were turned off by the negative tenor of the debate and felt that it wouldn't make a difference in their quality of life which politician was in power. Several people brought up the standstill over the debt ceiling last summer, as well as ignored promises of immigration reform, to explain their aversion to politics.

"How do you bring people into the political process when they find politics itself so distasteful?" Manzano asks. "That's a high bar; that's a tough challenge."

Obama's immigration announcement could make a difference, however. A Latino Decisions poll of 775 registered Latino voters released Sunday found that half of those polled said the announcement made them more enthusiastic about Obama. That finding is key, since a majority of Latino voters said in previous polls that they were less enthusiastic about Obama today than in 2008. But the poll doesn't tell us anything about unregistered Latino voters, whose attitude toward the announcement remains a mystery. Manzano, however, thinks it could help Obama with them, as well.

"This is going to provide a boost to people who are registered voters and maybe were feeling unenthusiastic or left out of the conversation, and potentially to people who are unregistered as well," Manzano says.