In the poll, Obama led Romney 46%-45%, a twelve-point change since January when Obama led 51%-38%. Romney has consistently given Obama his toughest challenge in head-to-head matchups. The latest TPM Poll Average gives Obama a 47.3%-44.3% edge over Romney.
Obama also topped Huckabee 48%-43% in the most recent poll, though he led the former Arkansas governor by a wider 50%-38% split last time around. And while Obama bested Palin 56%-34%, that 22-point gulf is smaller than the 26-point margin he held in January when he led Palin 56%-30%.
The poll also paired Obama against Donald Trump for the first time. Obama comfortably led that contest, topping Trump 54%-38%.
Obama's dwindling leads in hypothetical 2012 pairings coincides with a slide in his approval rating since January. Obama got a New Year's bump after signing a number of popular initiatives at the end of last year -- such as the repeal of Don't Ask, Don't Tell -- and rode into 2011 with a burnished reputation.
His high marks have since receded. In January, a Marist poll showed that 54% of Americans approved of Obama's job performance, compared to 43% who disapproved. By this month, Marist found Obama's approval rating underwater, with 50% of adults disapproving of his job performance versus 47% approving of it.
The TPM Poll Average also shows a recent downward trend in Obama's approval rating.
The Marist poll was conducted April 10-14, and surveyed samples of 532 and 552 registered voters nationwide. It has a margin of error of 4.5%.