Surprise! Maryland could determine control of the Senate this fall.

Democrats have plenty of things to worry about this fall, but until recently, hanging on to deep-blue Maryland’s opening U.S. Senate seat was not one of those things. That was until Feb. 9, mere hours before the filing deadline, when former governor Larry Hogan — a moderate Republican who left office last year with a stratospheric 73 percent approval rating — declared he was running. Now, “the future control of the United States Senate will come down to Maryland,” says Sen. Chris Van Hollen, a Democrat who occupies the state’s other seat.