Sen. John McCain said Sunday that the potentially powerful Hispanic vote in the upcoming presidential election remains “up for grabs” because neither President Barack Obama nor Republicans 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.”