The news network reported Sunday that Obama, the junior senator from Illinois, is within one superdelegate of Clinton.

The New York senator has picked up the votes of two superdelegates but lost one to Obama, bringing Clinton's superdelegate count to 273 and Obama's to 272.

Clinton's narrow lead is in sharp contrast to the lead she had in the beginning of the year, when she led the superdelegate race by more than 100, CNN said.

Since neither Clinton nor Obama is likely to clinch the necessary 2,025 delegates in the state-by-state primary race, superdelegates will almost certainly choose the Democratic Party's presidential nominee.

Obama leads the race for delegates, with 1,592 to Clinton's 1,424.

There are 217 pledged delegates up for grabs in the remaining state contests, including West Virginia, which holds its primary Tuesday.