Maryland's Senate race heats up as Cardin announces retirement.

Sen. Ben Cardin (D-Md.) announced his retirement, opening the door to a fierce battle on the left to fill a rare open Senate seat in the deep blue state. Three possible candidates lead the pack of contenders to replace Cardin: Reps. David Trone (D-Md.), Jamie Raskin (D-Md.) and Prince George’s County Executive Angela Alsobrooks (D). Former Gov. Larry Hogan (R) is the only viable contender on the GOP side. An open Senate seat is a once-in-a-blue-moon occurrence for Maryland, which has not seen an open seat in the upper chamber since former Sen. Barbara Mikulski (D) retired in 2017.