Democratic Presidential candidate Hillary Clinton campaigned for former Maryland gubernatorial candidate Anthony G. Brown. Now a congressional candidate, Brown endorsed Clinton for president. (Matt McClain/The Washington Post)

Former Maryland lieutenant governor Anthony G. Brown, who is a candidate in the state’s 4th Congressional District race, announced early Monday that he is endorsing Hillary Clinton for the Democratic Party nomination for president.

Brown declared his support for Clinton in an email from his congressional campaign one day before the New Hampshire primary, citing the former secretary of state’s advocacy of pre-kindergarten programs such as Head Start and work on gun control issues.

The endorsement comes a week after his onetime boss, former governor Martin J. O’Malley (D), dropped out of the race. Most of the state’s Democratic political establishment is backing Clinton in her bid for the presidency.

“The stakes for our country are high and the people of Maryland deserve a strong leader and ally in the White House,” Brown said in the email. “We’ve seen the remarkable progress made under President Obama, but we still have a long way to go to bring that progress back here to the 4th district.”

Clinton, who campaigned for Brown during his failed gubernatorial bid in 2014, is locked in an increasingly tight primary race against Sen. Bernie Sanders of Vermont for the nomination.

Brown, meanwhile, is running against five other candidates, including a former Prince George’s state’s attorney and an Annapolis lawmaker, to replace Rep. Donna F. Edwards (D-Md.), who is running for the Senate to fill the seat of retiring Sen. Barbara A. Mikulski (D-Md.).