Baltimore County Executive Kevin Kamenetz announces he is running for governor. (Brian Witte/AP)

Baltimore County Executive Kevin Kamenetz (D) announced Monday that he is running for governor, bringing a long résumé in local government and state politics to a crowded Democratic primary race.

Kamenetz, who declared his candidacy in front of about 100 people outside a county building in Towson, has been an outspoken critic of Gov. Larry Hogan (R), ripping the GOP leader for his opposition to a 2017 bill that would have limited police cooperation with immigration enforcement efforts and Hogan's veto of a measure to require businesses with at least 15 employees to provide paid sick leave.

"I am the best Democrat in this race to take on Larry Hogan and take back the state from the likes of Donald Trump and [U.S. Attorney General] Jeff Sessions," he said Monday.

Kamenetz, 59, is finishing his second term as executive, after 16 years on the County Council. The lifelong Baltimore County resident was a member of the Democratic State Central Committee for 12 years and serves as president of the Maryland Association of Counties.

This year, he directed Baltimore County police not to participate in efforts to identify undocumented immigrants among college students, and he signed an order barring county law enforcement from inquiring about immigration status or holding detainees past their release dates on behalf of federal deportation authorities unless the agents have presented a judicial warrant.

Prince George's County Executive Rushern L. Baker III, former NAACP president Ben Jealous, state Sen. Richard S. Madaleno Jr. (Montgomery), entrepreneur Alec Ross, Baltimore attorney and former University System of Maryland Board of Regents chairJames L. Shea, and Krishanti Vignarajah, a onetime policy director for former first lady Michelle Obama, also are planning to compete in the June 2018 primary.

Policy consultant Maya ­Rockeymoore is weighing a bid for the Democratic nomination, as well. Former state attorney general Douglas F. Gansler, who also thought about running, said Monday that he has no plans to do so.

Kamenetz won reelection in 2014 with 56 percent of the vote, defeating Republican George Harman. But Hogan won 59 percent of the vote in Baltimore County that year, a key factor in his upset victory over Democratic nominee and then-lieutenant governor Anthony G. Brown.

As county executive, Kamenetz helped launch a $1.3 billion initiative to renovate schools and build new ones. He also helped facilitate a deal to redevelop a shuttered steel mill into a site where large corporations plan to run logistics operations.

He said that as governor, he would improve the state's educational system and fight for workers, including by pushing for a $15 minimum wage and expanding job-training programs.

Kamenetz has appeared to be laying the groundwork for a possible gubernatorial bid for more than a year, hosting a late-night party for Maryland Democrats at last summer's Democratic National Convention and distributing a daily "Kamenetz Chronicle" newsletter to the state's convention delegates and guests.

His campaign launch got a premature burst of attention Sunday, when The Washington Post reported that a top aide to ­Kamenetz had sent an email to county government employees, possibly in violation of state ethics rules, urging them to attend Monday's announcement. Several government employees were at the event.

"For a county official to be promoting, through his county email, for county employees to come to a campaign event is a violation," said Jennifer Bevan-Dangel, executive director of the good-government group Common Cause Maryland. "The presumption from that email would have been: Come as part of your job, which is another big red flag."

Kamenetz did not take questions after Monday's event. His campaign spokesman, Sean Naron, said Sunday that "any government employee, even those less familiar with political rules, should abide by them."

At least eight state lawmakers attended Kamenetz's announcement, including Del. Dan K. Morhaim and Sen. Shirley ­Nathan-Pulliam, both Baltimore County Democrats who said they have not decided whom to endorse for governor.

Morhaim said Kamenetz has "done a lot of good for Baltimore County," adding that "there are a lot of good candidates." Nathan-Pulliam said she won't endorse anyone until next spring but is "proud of the work" the county executive has done.

Kamenetz had $1.6 million cash on hand for the 2018 election, according to his January campaign finance report. He and other candidates are not required to submit additional reports until 2018.