Rep. C.A. Dutch Ruppersberger, who briefly considered running for governor himself last year, endorsed Lt. Gov. Anthony Brown for the job on Tuesday.
The Baltimore County Democrat was one of the last holdouts in the congressional delegation to pick a candidate, along with Reps. Chris Van Hollen and John Delaney, both of Montgomery County. The other six Democrats in the state's congressional delegation are backing Brown.
"Lt. Gov. Brown has demonstrated a commitment to building a business climate that attracts, retains, and grows business in the 2nd Congressional District, and he has a plan to continue that success across our entire state," Ruppersberger said in a statement.
Ruppersberger, a six-term lawmaker, floated the idea he might run for the job last year but announced in January he would instead "continue to push for change in Washington." He was spottetd at a fundraiser for Brown in Potomac earlier this month that featured former President Bill Clinton.
Brown is running against Attorney General Douglas Gansler and Del. Heather R. Mizeur for the Democratic nomination.
Ruppersberger, a former Baltimore County executive, is likely to be an important endorsement for Brown's campaign as the candidates court voters in Baltimore County, the third-largest pool of Democratic votes in the state. Not since 1990 -- when Baltimore's William Donald Schaefer ran against William S. Shepard of Montgomery County -- have the major parties failed to nominate a Baltimore County native or resident for governor.
The primary is June 24. The endorsement was first reported by The Baltimore Sun.
"Working with Rep. Ruppersberger, we've made real progress in strengthening the Baltimore region's schools, attracting new employers and delivering better opportunities for all of our families," Brown said in a statement. "As we get closer to Election Day, I'm thankful momentum continues to grow for our vision to build a better Maryland for more Marylanders."