If Mitt Romney earlier this year faced an uphill battle with Latinos, the nation's fastest-growing voting bloc, that hill just turned into a mountain.

President Obama's announcement last Friday that his administration would not seek to deport up to 800,000 children of illegal immigrants has not only gone over predictably well with Latinos but with voters overall. Sixty-four percent of likely voters agree with Obama's policy, while 30 percent disagree, according to a new Bloomberg poll released Tuesday. While the new policy left voters divided along party lines - with 86 percent of Democrats in favor of it and 56 percent of Republicans against it - independents came out in favor of it, with 65 percent supporting the change.

"We're a better nation than one that expels innocent young kids," the president said Friday.

The new White House policy will offer temporary work permits to young illegal immigrants who came to this country as children. It is similar to the Dream Act, a Democratic proposal supported by Obama but shot down by Republicans, in Congress.

Get more pure politics at ABC News.com/Politics and a lighter take on the news at OTUSNews.com.

In addition, recent polls have shown a nearly double-digit jump in support for Obama among Latinos since he made the change, and Obama was already doing well among the country's largest ethnic minority. An ABC News/Washington Post poll earlier this spring revealed 73 percent of Latinos backed Obama, compared with 26 percent for Romney. While Latinos had previously expressed dismay about Obama's failures to enact comprehensive immigration reform despite enjoying a Democrat-controlled Congress for his first two years in Washington, his decision to loosen the deportation rules has boosted Latino enthusiasm for him.

"The announcement on June 14 appears to have clearly erased Obama's enthusiasm deficit among Latinos," said Matt Barreto, a researcher at Latino Decisions and associate professor of political science at the University of Washington.

The challenge for Obama will be making sure Latinos head to the polls come November. The number of registered Latino voters has dropped significantly in recent years, and projections of how many Latinos will vote in November, once as high as 12.2 million, according to the National Association of Latino Elected and Appointed Officials, or NALEO, now hover around 10.5 million, according to the William C. Velasquez Institute.

If boosting Hispanic turnout is key for Obama, who won 67 percent of the Latino vote in 2008, capitalizing on the economic struggles of Latinos may be Romney's best hope. The nominal Republican nominee denounced Obama's announcement last Friday as a political move and accused him of trying to distract Latinos from the economy. The jobless rate among Latinos is currently 11 percent, higher than the national average of 8.2 percent.

"I believe that the reason this came out is the president is trying to shore up his base with Latino voters, and he's also trying to change the subject from his miserable speech last week - from his gaffe that the private economy is 'doing fine' and from the failure of his economic policies to get this economy going again," Romney said in an interview with Fox News Radio.

In Romney's favor is the fact that Latinos have cited the economy - not immigration reform - as their top priority. Later this week, the battle for the Latino vote will be on full display in Florida, when both Obama and Romney address Latinos at the annual NALEO conference in Orlando. Romney will speak to the group on Thursday, with Obama taking the stage the following day. At this moment, now more than ever, the latter clearly has the upper hand among Latinos, an advantage that could ultimately secure him a second term in the White House.

Matthew Jaffe is covering the 2012 campaign for ABC News and Univision.