Incumbent Sen. Bob Casey (D) is trailing his Trump-backed Republican challenger David McCormick in Pennsylvania's U.S. Senate race, which remains too close to call.
The big picture: Democrats are on defense after Republicans seized back control of the chamber. The only question now is the size of the GOP's majority.
There was more than $300 million in ad spending and ad reservations reported as of September, per AdImpact data.
Zoom in: Casey, who's held the seat since 2007, is seeking a fourth term. In the closing stretch, he's made attempts to cast himself as more moderate — even boasting about his ties to now President-elect Trump.
The senator has focused his campaign on corporate price gouging, and he opposes tax cuts for the ultra-wealthy.
McCormick, a former hedge fund CEO, is running for office again after losing the Republican Senate primary to TV personality Mehmet Oz in 2022. McCormick was on stage with Trump during the attempted assassination of the former president in Butler in July.
McCormick wants to tamp down on inflation, and he's called for stricter immigration policies.