From Gallup, "Party Affiliation Gap in U.S. Narrowest Since 2005: Democratic advantage shrinks as more independents lean to the Republican Party":
The advantage in public support the Democratic Party built up during the latter part of the Bush administration and the early part of the Obama administration has all but disappeared. During the first quarter of 2010, 46% of Americans identified as Democrats or leaned Democratic, while 45% identified as or leaned Republican.More at the link (via Memeorandum). See also, Ed Morrissey, "Gallup: Party affiliation gap narrows to one point."
The survey interviews date from January, where at that point the new administration had been in power for less than a year. This has to be some sort of record. President Obama's destroyed the brand and, amazingly, die-hard Obama Zombies are going down with the ship in massive numbers.