Sen. Barack Obama is projected to win Pennsylvania, according to the Associated Press and major news networks.

Sen. John McCain had considered Pennsylvania’s 21 electoral votes key to his path to victory. Pennsylvania, along with Florida and Ohio, has played a crucial role in the past several presidential elections, and no candidate has won the presidency without winning two of those three states since 1960, according to Reuters.

Many election watchers had considered Pennsylvania the only 2004 blue state that McCain had a chance to capture this year.

“McCain really has no choice but to give Pennsylvania a lot of attention, because it is the only fairly large state that Kerry won where McCain has any real chance of winning,” University of Pennsylvania political science professor Rogers M. Smith told CBS NEWS last week.

The last Republican presidential candidate to win the state was George H.W. Bush in 1988, but George W. Bush lost to Sen. John Kerry by only 2.5 percentage points in 2004. And Obama had struggled in Pennsylvania during the primaries, losing the state to Sen. Hillary Clinton by 10 points after failing to win over working-class white voters in the western part of the state.

Still, as Election Day approached, Pennsylvania appeared to be tilting Obama’s direction, with an average of polls putting him up 7.3 points, according to RealClearPolitics.com.