He previously served as a member of the Maryland House of Delegates from 1994 to 2003, representing District 22B in northern Prince George's County.

[1] His father, Rushern Jr., was an officer in the United States Army Special Forces and served in the Vietnam War and his mother, Carolyn, worked as a nurse's aide.

[6] Afterwards, Baker enlisted in the United States Army Judge Advocate General's Corps, serving from 1987 to 2001 and attaining the rank of captain.

Senator John Kerry for one year, afterwards working as a contract complaints officer in the District of Columbia Department of Housing and Community Development from 1987 to 1989.

[10] He supported bills to ban discrimination on the basis of sexual orientation,[11] require the state to translate all public documents and forms into Spanish,[12] and limit the powers of the Prince George's County Board of Education.

[14] He targeted women voters and enjoyed a boost in momentum after The Washington Post endorsed his campaign during the Democratic primary,[15] but continued to trail county state's attorney Jack B. Johnson in polling up to election day.

[18] He declared his candidacy in January 2006, and ran a campaign criticizing Johnson's handling of crime and education in Prince George's County.

[21] He won the Democratic primary in September 2010, defeating Prince George's County Sheriff Michael A. Jackson, who was backed by Johnson,[22] and state delegate Gerron Levi with 43.9 percent of the vote.

Revitalization projects in the county's underserved communities and major development projects—including the MGM National Harbor casino, the University of Maryland Capital Region Medical Center, and the Purple Line transit line—broke ground under his administration.

[27] He unsuccessfully sought to raise property taxes in Prince George's County to pay for education reforms and supported a failed referendum that would have increased the number of terms that county-elected officials could serve from two to three.

Under Maxwell's tenure, the school system lost $6.4 million in federal Head Start grants after a review found that county officials failed to address complaints that teachers in the program were humiliating and using corporal punishment against students;[28] and was the subject of a state probe that found that the grades of nearly 5,500 students were altered between 2015 and 2017, which prompted the Maryland State Board of Education to assign a monitor to prevent future grade manipulation.

Senator Chris Van Hollen,[38] U.S. Representative Steny Hoyer,[39] Attorney General Brian Frosh,[40] Montgomery County Executive Isiah Leggett,[41] and former governors Parris Glendening[42] and Martin O'Malley.

[44] Baker was defeated by former NAACP president Ben Jealous in the Democratic primary election on June 26, 2018, placing second with 29.3 percent of the vote.

[51] He also criticized the leaked draft majority opinion for the U.S. Supreme Court case Dobbs v. Jackson Women's Health Organization.

The family decided to speak publicly about her diagnosis in 2012 in order to increase awareness for the disease and advocate for greater funding for medical research.