Arizona Sen. John McCain says that the powerful Latino vote is still up for grabs in upcoming 2012 Presidential election.

McCain adds that neither President Barack Obama nor the Republican Party have convinced these voters that they are on their side.

The one-time GOP presidential hopeful, whose own 2008 candidacy was shaped in part by immigration, said that large Hispanic populations in his home state of Arizona and elsewhere are listening carefully to what Republican candidates have to say on immigration and could become a "major factor" in 2012.

"I think that the Republican party has to discuss this issue in as humane way as possible," he said. He later added, "the enthusiasm on the part of Hispanics for President Obama is dramatically less than it was in 2008, because he has not fulfilled his campaign promises either..

So I view the Hispanic vote up for grabs."

McCain comment, on CNN's "State of the Union," is a warning to the GOP primary candidates who have mostly embraced a hardline on immigration, lest they be accused of supporting any kind of "amnesty" for the some 12 million undocumented immigrants estimated to be living in the U.S.

Newt Gingrich was most recently attacked by his opponents for saying he would conditional grant legal status to those with longstanding family and community ties; he has since endorsed a South Carolina law that allows police to demand a person's immigration status.

McCain said he believes the Hispanic vote could sway Arizona, Colorado and New Mexico.

The key, he said, was for Republicans to address immigration in a humane and pragmatic way that every voter could appreciate.

More specifically, McCain said, GOP presidential candidates should find a way to address the status of undocumented immigrants already in the country while finding a way to secure the border to deter others from crossing the border.

"It's a careful balance of addressing this issue, which I think the majority of Hispanics would appreciate. . . . We have to have empathy. We have to have concern. We have to have a plan," he said.

In 2008, McCain watched his own standing in the election suffer when he backed a plan to give some undocumented immigrants an eventual path to citizenship.

Gingrich has challenged his GOP opponents to come up with their own plans for dealing with the millions inside the U.S. illegally.

"What is it that you're going to do? Are you really going to go in and advocate ripping people out of their families?" he said.

In 2008, Mitt Romney had supported the idea of allowing some undocumented immigrants to sign up for permanent residency or citizenship. More recently, he has said it would be a "mistake" for the GOP to allow anyone to "jump ahead of the line" and characterized Gingrich's approach as a "doorway" to amnesty.

In the interview Sunday, McCain declined to comment on the position of individual candidates. "I respect the views of the voters," he said.

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