Democrats ousted the Republican mayors in the Maryland cities of Frederick and Annapolis.
Frederick Mayor Randy McClement conceded to Democratic Alderman Michael O'Connor on Tuesday night.
According to unofficial tallies, O'Connor received about 58 percent of the vote, while McClement got about 36 percent.
McClement was hoping to serve a third term after having been the city's mayor for the past eight years.
In Annapolis, Democrat Gavin Buckley unseated first-term Republican mayor Mike Pantelides. Unofficial tallies show that Buckley won with about 62 percent of the vote.
College Park Mayor Patrick Wojahn defeated three challengers to win a second term.