U.S. President Joe Biden and Republican challenger Donald Trump go before voters on Tuesday's primaries in the battleground state of Pennsylvania, one of the last tests of voter enthusiasm ahead of November's general election. Pennsylvania, with 19 Electoral College votes toward the 270 needed to win, is a top prize and a toss-up in the 2024 presidential election featuring a Biden-Trump rematch. In 2020, Biden won Pennsylvania by less than 1.5%, or roughly 80,000 votes.