Sen. John Fetterman (D-PA) warned Democrats not to underestimate former President Donald Trump’s formidable following in Pennsylvania, a battleground state Vice President Kamala Harris wants to win in order to secure the election this fall.

Speaking at the Atlantic Festival on Thursday, the Pennsylvania senator predicted that the presidential race in the state would be closer than some in his party might think. He argued that Trump’s influence has only spread since he narrowly survived an assassination attempt at a Pennsylvanian rally two months ago.