Prince George's County Executive Rushern Baker III (D) will announce in a video message Wednesday that he is running for governor. (Astrid Riecken for TWP)

Prince George’s County Executive Rushern L. Baker III announced Wednesday that he is running for governor, sending a video message to news outlets and supporters that explains why he believes he can emerge from a crowded field of Democrats to challenge popular Republican Gov. Larry Hogan’s bid for a second term.

Baker, 58, is midway through his seventh year as leader of the state’s second-largest jurisdiction. He has focused on eliminating the corruption that used to be a hallmark of the county’s government as well as improving schools and services and stimulating economic growth.

A former state lawmaker with a law degree from Howard University, Baker would become Maryland’s first African American governor and the first county executive to serve in the role since Parris N. Glendening (D), also of Prince George’s, did from 1995 to 2003.

“Being county executive gives me a good vantage point to look at Maryland as a whole, because we are urban, suburban and rural,” Baker said in an interview before his campaign announcement.

“When I look at what we had to do in Prince George’s, given the circumstances we were in, and I look at the state, it’s not dissimilar,” he added.

Rushern L. Baker III, left, and his wife, "Sissy" Christa Beverly, hug their son, Rushern L. Baker IV, center, in 2011. (family photo/FAMILY PHOTO)

Former NAACP leader Benjamin Jealous and Baltimore tech entrepreneur Alec Ross have also launched campaigns for next June’s Democratic primary, and state Sen. Richard S. Madaleno Jr. (Montgomery) says he will run as well. Rep. John Delaney, former state attorney general Doug Gansler, Baltimore County Executive Kevin Kamenetz and Baltimore lawyer James Shea are strongly considering running.

The contest could lay bare the differences between the party’s progressive and establishment factions, which bubbled to the surface this year during legislative battles and the selection of Kathleen Matthews as Democratic state party chair.

But Baker rejected the notion of a divided party, saying he believes all voters want jobs, expanded business opportunities and quality education, whether they are progressives, conservative Democrats or tea party Republicans.

“I don’t see it. I don’t know where it is,” Baker said about a party divide. “The beauty of the Democratic Party is that it’s a big, broad tent. At the end of the day, voters want to know what you can get done.”

The son of a U.S. Army Special Forces officer and a nurse’s aide, Baker was born in Georgia. His family moved frequently, including stints in Okinawa, Japan, before settling in Massachusetts, when he attended high school.

After law school, Baker worked on Capitol Hill, in the D.C. government and as legal counsel for a nonprofit community development and social services organization.

He married his college sweetheart, civil rights lawyer Christa Beverly, and settled in Prince George’s, where he forged ties with fellow black politicos, including Wayne K. Curry, the late county executive. In 1994, with Curry’s guidance, Baker won a seat in the House of Delegates representing Cheverly and parts of Bladensburg.

But Baker badly wanted to be county executive. He lost two primary races, the first while serving in the House of Delegates. In 2010, he tried again and defeated four other Democrats in the primary, later easily winning the general election. Days later, federal agents arrested outgoing county executive Jack B. Johnson (D) on corruption charges.

Baker has traveled the state for months, sharing his story of an economic and civic resurgence in Prince George’s County, the only majority-black jurisdiction in Maryland besides Baltimore City and one of the most affluent majority-black jurisdictions in the nation.

In addition to pushing through ethics reform and seizing partial control of the struggling school system, Baker has boosted development around Metro stations and shepherded major projects, including a regional medical center slated to break ground in the fall. He abandoned his initial opposition to gambling in the county and became a major supporter of the glittering MGM National Harbor casino, which opened to rave reviews in December.

Baker has drawn criticism for the slow pace of change and for continued problems with schools, including recent allegations that officials doctored grades and records to push up graduation rates.

Some of his initiatives have failed, among them a wildly unpopular, double-digit tax increase that was rejected by the County Council and an attempt to increase the number of terms that county-elected officials can serve from two to three, which voters soundly defeated.

Baker has sparred with Hogan over funding for the Purple Line light rail and the medical center. He says he has taken political risks in the name of progress and accuses Hogan of “passivity” while in office.

“There’s no risk at all, no definitive ‘Here’s where I want to take us,’ no line in the sand,” Baker said of the governor, who has high approval ratings and a huge campaign war chest to boost his reelection chances.

Before launching his campaign, Baker said he had to decide whether he thought he could do a better job than Hogan. That was the standard that Baker’s wife, whom he calls the driving force in his political career, had set in his previous races.

Beverly was diagnosed with early onset dementia in 2012. Her condition has deteriorated considerably, but the county executive still includes her — along with their three adult children — in campaign meetings and conversations.

Her illness, Baker said, has increased his awareness of “the issues facing working men and women” who juggle work and caretaking. It’s also made him impatient about implementing public policy.

“Time is a precious commodity,” Baker said. “People want to know what you can do now.

“And I understand it, because I don’t know what tomorrow is.”