Republican Donald Trump has scooped up Pennsylvania's 20 electoral votes.
Members of Pennsylvania's 58th Electoral College met at the state Capitol amid demonstrations by hundreds of protesters to cast the state's 20 electoral votes for Trump.
Trump beat Democrat Hillary Clinton in Pennsylvania by fewer than 45,000 votes out of more than 6 million cast, or by less than 1 percent.
The result led to clapping from supporters and boos from the gallery, with yells of "Shame on You."
Pennsylvania's 20 electoral votes are fifth-most in the nation, and gave Trump a critical boost to winning the White House when he became the first Republican since 1988 to win the state.
Monday's outcome was in little doubt, since the electors were senior members of the Republican Party hierarchy in Pennsylvania, GOP activists or ardent Trump loyalists picked by his campaign.
