ispanics - the nation's largest and fastest-growing minority voting bloc - are loyal Democrats and supporters of President Obama in the 2012 election, but a majority have not yet engaged in the campaign, according to a new Pew Hispanic Center study.

Two-thirds of Latino registered voters identify as Democrats, and 68 percent say they'd support Obama over former Massachusetts Gov. Mitt Romney in a hypothetical match-up.

But more than half - 56 percent - of Latino registered voters say they've given little or no thought to the presidential candidates in the race. And their approval of Obama and the direction of the country lingers around 50 percent.

"It is just under a year out from the election, and things may change as we move through 2012, but at this moment, in this snapshot, we see that many Latinos have not given much thought to the candidates who are running," said Mark Hugo Lopez, associate director of the Pew Hispanic Center.

This dynamic signals that the president's reelection campaign will need to continue efforts to engage and mobilize Hispanics - a constituency that aides say will be crucial to victory on Nov. 6.

The figures also cast doubt on Republican claims about making inroads with Latino voters. More Latinos consider themselves Democrats than Republicans by a 47 percentage point margin - a gap that grew 10 points since 2010.

"Even though we do see a decline in the president's approval rating among Hispanics, support for him remains just as strong as it was in 2008," Lopez said.  "And Obama's margins of victory against Romney and [Texas Gov. Rick] Perry in a hypothetical match-up are nearly as strong if not as strong as they are for the 2008 election."

Obama's campaign strategists regularly cite the growing Hispanic electorate as an advantage, particularly in battleground states with significant populations of Latino voters.

Nationwide, the number of Hispanic Americans eligible to vote has grown by 2 million since 2008, and now totals an estimated 21.7 million eligible voters, according to the Pew Hispanic Center.

States with surging Latino populations, like Colorado, Georgia and Arizona, are particularly attractive to the Obama campaign.

"We really look at Arizona and see a state where we can go and expand the electorate, register a whole bunch of young people and traditional Democrats and Latinos that have never been registered before," Obama campaign manager Jim Messina told ABC News last month.

Obama won 67 percent of the Hispanic vote in 2008 to John McCain's 31 percent.

A senior Republican strategist said the party has taken a close look at the demographics in Georgia and Arizona but insists any modest growth in the Hispanic electorate this year doesn't mean those states will turn blue in 2012.

"It's something we're paying attention to and what [the Obama campaign] sees there. We've run the numbers and even with Hispanic voters we just don't see it," the official said, adding "we are taking extra precautions though."

If Republicans nominate frontrunner Romney, however, the Pew study suggests he could be in for a serious uphill climb.

Only 23 percent of Latino registered voters back him in a match-up with Obama.  Strategists of both parties say the Republican nominee would need to win between 35 and 40 percent of the Hispanic vote to win the 2012 election.

"Gov. Romney is on the wrong side of the issues important to Hispanic voters and it's clear that Hispanics recognize that," said Obama campaign spokeswoman Gabriela Domenzain.