Obama is understandably most popular among Democrats, who like her by a 79-2 percent margin. Among independents, Obama's favorability ranks 43-11 percent, while she is underwater among Republicans, with a 30 percent unfavorability to 24 percent favorability ranking.

More women say they approve of Obama (57 percent) than men (44 percent), although men are more likely to simply not have an opinion.

On Thursday, the firs lady's office announce a new Twitter feed for Obama. White House press secretary Jay Carney said he wouldn't "ruin the surprise" of how the first family was celebrating her birthday on Thursday.