RICHMOND — Del. Mark H. Levine on Monday will declare himself a candidate for lieutenant governor of Virginia, becoming the 12th contender to jump into the 2021 race.

A lawyer first propelled into political activism by the murder of his sister in 1996, Levine (D-Alexandria) promised to work across the aisle to address issues ranging from economic opportunity to domestic violence.

“Injustice really gets under my skin,” Levine said in a written statement ahead of his announcement. “All our lives we’ve been told ‘that’s just the way things are.’ But I’ve found — if you’re persistent and creative, get the details right, and work with others of good will — even the toughest problems can be solved.”

If elected, Levine, 54, would become Virginia’s first openly gay statewide elected official as well as the first Jewish person elected statewide.

Virginia Democrats will pick their nominee in a primary this summer. Other contenders are: Del. Hala S. Ayala (Prince William), former Virginia Democratic Party chairman Paul Goldman, Del. Elizabeth R. Guzman (Prince William), Norfolk City Council member Andria P. McClellan, Fairfax County NAACP President Sean Perryman, Del. Sam Rasoul (Roanoke) and Arlington County businessman Xavier Warren.

The Republican field includes: Fairfax County business consultant Puneet Ahluwalia; Lance Allen, a national security company executive who lives in Fauquier County; Del. Glenn R. Davis Jr. (Virginia Beach); and former delegate Timothy D. Hugo (Fairfax).

Lt. Gov. Justin Fairfax (D) is running for governor.

The lieutenant governorship is intended to be a part-time post with just two constitutional duties: to take over if the governor dies or resigns and to preside over the state Senate, including casting votes in case of a tie. But the post is highly sought after as a potential steppingstone to the Executive Mansion.

Levine said he would devote himself to the position full time, crisscrossing the state as the eyes and ears of the governor, who is elected independently.

A native of Nashville who attended Harvard University and Yale Law School, Levine has represented Alexandria and parts of Arlington and Fairfax counties since 2016.

He spent a decade fighting to put his brother-in-law behind bars (he was eventually sentenced to 56 years) and working on domestic-abuse and custody laws that helped his parents win custody of his niece and nephew.

Levine helped establish one of the nation’s first same-sex marriage advocacy groups in 1999, co-founding Marriage Equality California, where he then lived. In the General Assembly, he teamed up with a conservative Republican, Sen. Amanda F. Chase (Chesterfield), to co-found the Transparency Caucus, which successfully pushed for live-streaming and archiving of committee and subcommittee meetings.

Chase is now running for governor.