(CNN) - Democrat Barack Obama will win Pennsylvania, CNN projects, based on exit polls and partial results.
The victory gives Obama 21 electoral votes and deals Republican John McCain a serious blow. He and his running mate Gov. Sarah Palin had campaigned heavily, making 10 vists in the last 15 days of the campaign.
Obama has 102 electoral votes to McCain's 34, according to the latest CNN projections. A candidate needs 270 to win.