Deep-blue Maryland has been a stronghold for Democrats in general elections for decades. But with a popular former Republican governor running for an open Senate seat and eight House races, the Old Line State could spring a few surprises this November. In this series, Old Line, New Battles: Maryland feels the primary pinch, the Washington Examiner will look at the key figures and important issues six months until election day. Part four will focus on Maryland’s three House open races.

Maryland‘s three open House races have drawn large primary fields as both Democratic and Republican hopefuls seek to replace three Democratic incumbents.

The state, which has eight House races on its May 14 primary ballot, had three incumbents decide to not pursue another term in their Districts, with two opting to retire, while a third, Rep. David Trone (D-MD), who represents Maryland’s 6th district, decided to launch a bid for retiring Sen. Ben Cardin’s (D-MD) Senate seat.

In the 2nd Congressional District, Rep. Dutch Ruppersberger (D-MD), who served 11 terms in Congress, announced his retirement earlier this year. His decision to leave his long-held seat came amid a wave of announcements from House incumbents who decided to not seek reelection, including fellow Maryland Democratic Rep. John Sarbanes (D-MD) in the state’s 3rd Congressional District.

Here’s a look at Maryland’s three open House races ahead of Tuesday’s primaries: