WASHINGTON (CNN) -- New York Sen. Hillary Clinton, D- New York, has a 15-point edge over Sen. Barack Obama, D-Illinois, in the race for the Democratic presidential nomination, a CNN/Opinion Research Corporation poll released Wednesday finds[PDF].

Clinton registered at 37 percent -- three percentage points higher than a similar CNN/Opinion Research Corporation poll conducted in January. Obama drew 22 percent -- a four-point increase from the January poll.

Former Vice President Al Gore, at 14 percent, and former North Carolina Sen. John Edwards, at 12 percent, rounded out the candidates polling in double digits. The rest of the field drew a combined six percentage points.

The poll also finds that if Gore chooses not to run for president, most of his supporters will go over to Clinton. If Gore is not in the race, Clinton draws 44 percent, seven percent higher than if Gore did run. Edwards improves his showing by four percentage points and Obama by one in a Gore-less field.