Speaking in Evansville, Ind., Tuesday night, Obama said he looked forward to the upcoming nominating contests in Indiana and North Carolina on May 6.

Months before the Pennsylvania primary, Clinton led Obama by double digits. He managed to close much of the gap after weeks of campaigning.

With 93 percent of the precincts reporting in Pennsylvania, Clinton led Obama by 10 points, 55 percent to 45 percent, CNN reported.

"We rallied people of every age and race and background to the cause. And whether they were inspired for the first time or for the first time in a long time, we registered a record number of voters, and it is those new voters who will lead our party to victory in November," Obama said.