Democratic Sen. Bob Casey will seek a fourth term in office, bringing the power of incumbency and unmatched name recognition in Pennsylvania politics to his party’s defense of a seat in a critical presidential battleground state. The announcement by Casey, the longest-serving Democratic U.S. senator in Pennsylvania history, gives Democrats a boost ahead of a difficult 2024 Senate map. They must defend incumbents not only in red states – Montana, Ohio and West Virginia – but also in multiple swing states. Casey, who will turn 63 in a few days, is a key ally of labor unions and President Joe Biden. In Congress, Casey, a moderate Democrat, has backed all of Biden’s top priorities and forged a close relationship with the president.