Former Utah Gov. Jon Huntsman is known by only 32 percent of all voters and 35 percent of Republicans. In a troubling sign for the man who until recently served as Obama's ambassador to China, 36 percent of Republican voters familiar with Huntsman say there is "no chance" he would earn their support. Huntsman's silver lining: Of the presidential hopefuls tested, only former New Mexico Gov. Gary Johnson registered lower name-recognition among Republicans. Republican voters are lukewarm on former Minnesota Gov. Tim Pawlenty. Slightly more than half of Republicans, 52 percent, have heard of Pawlenty, and 27 percent of those familiar with him say there is a "good chance" they would vote for him. Whichever Republican emerges from the field to challenge Obama faces an uphill climb, according to the poll. A majority of voters approves of the job Obama is doing as president, and 48 percent of voters say they would prefer to see Obama re-elected in 2012, compared to just 37 percent who would prefer a Republican win the election. The Pew Research Center poll was conducted May 25-30, surveying 1,227 registered voters, for a margin of error of +/- 2.8 percent. There were 535 Republican and Republican-leaning independent voters; those results carry a margin of error of +/- 4.2 percent.