From Public Policy Polling:

Public Policy Polling’s fifth monthly survey looking at how Barack Obama does when matched up against possible 2012 opponents reaches the same key conclusions all of the other polls did: Obama leads all comers, and Mike Huckabee is the strongest Republican at this point.

In this month’s iteration of the survey Huckabee polls the closest to Obama of any match up so far, trailing the President just 47-44. A month ago the spread was 48-42. Newt Gingrich comes the next closest, trailing 49-41, followed by Mitt Romney at 47-40 and Sarah Palin at 52-38.

In addition to coming the closest to Obama, Huckabee also has the best favorability rating of the group. 45% of voters have a positive opinion of him to just 28% unfavorable. The other Republican with a net positive rating, at 37/34, is Mitt Romney.

A plurality of voters have a negative opinion of both Sarah Palin and Newt Gingrich. For the former Alaska Governor it’s 49% unfavorable to 40% favorable, and for the one time Speaker of the House it’s 42% unfavorable to 33% favorable.