At the time, Johnson was the first out gay man to serve as speaker, and the only openly HIV-positive politician in New York State.

[2] In 2019, Johnson announced he was running for mayor of New York City, but he stopped fund-raising in March 2020, and in September 2020 withdrew from the race, saying he had had depression since May 2020 and did not think he could campaign and be effective as speaker while monitoring his mental health.

[citation needed] Johnson was born in Beverly, Massachusetts, and raised in nearby wealthy Middleton, by his mother, Ann Queenan Richardson (who worked at a variety of jobs, including at a thrift shop that she founded and manages),[4] and his stepfather, Rodney Richardson, owner of Middleton Tire Service and a truck driver.

[4] Johnson made national headlines in 2000 when, while co-captain of the Masconomet Regional High School football team, he publicly came out as gay.

[28] Johnson's legislation to require transparency regarding health services administered at Rikers Island was signed into law in June 2015.

"[31] In 2017 Johnson along with others occupied the offices in the U.S. Capitol of Senate Republicans to protest efforts to repeal the Affordable Care Act, and was arrested and zip-tied.

[36] He later tweeted, "By occupying offices of Senate Republicans, we demand they cease attempts to strip health care from millions!

[37] In 2018, Johnson sponsored a new law requiring that inmates in New York City jails be provided with free telephone calls.

[39] Johnson supports making it legal for sex workers to provide sexual services, but not for their clients to be free from criminal prosecution.

[40] In 2014 Johnson introduced legislation to remove surgical requirements for transgender New Yorkers to change the gender on their birth certificates.

[42] In June 2019, to mark the 50th anniversary of the Stonewall riots, sparking the start of the modern LGBTQ rights movement, Queerty named Johnson one of the Pride50 "trailblazing individuals who actively ensure society remains moving towards equality, acceptance and dignity for all queer people".

[45] Johnson spoke out against it, due to the evangelical Christian aid group's requirement that their employees commit to a statement of faith, including a traditional view of marriage and sexuality.

[48][49][52] Johnson worked with Council member Elizabeth Crowley in 2014 to introduce a set of bills to regulate the sale of pets in New York City, with the purpose of animal rights protection.

[54] In 2015 Johnson introduced legislation mandating that either fire sprinklers or supervision be present in all establishments that house animals for more than 24 hours.

[56] In October 2016 he held a hearing in the Health Committee and spoke in support of the legislation, saying to the media that "trucking wild animals in and out of the city strictly for entertainment purposes is not a humane way to be treating them".

"[60][67] Larry Cowit, vice president of Madison Avenue Furs, mused: "There has to be a line, or we're all going to eat tofu and walk around in plastic sandals.

The slope is slippery ... Johnson and the Council enjoy the symbolism of a fur ban, but they wouldn't dare go after the many other ways humans benefit from inexpensive and plentiful protein and, well, just plain tasty food.

[70] Johnson introduced legislation with Council member Vanessa Gibson to require the NYC Department of Education to report on the use of disciplinary measures in public schools.

[72] Johnson was the prime sponsor of legislation declaring a housing shortage emergency in 2015, which allowed rent stabilization laws to be extended.

[3] In March 2021, he launched his run[84] for the 2021 New York City Comptroller election, but lost the Democratic primary, 51.9%–48.1%, to Councilmember Brad Lander.

[85][86] Sanders and other sources mention other close ties to lobbyists,[87] especially the Kasirer lobbying firm, as one of its vice presidents, Jason Goldman, served as Johnson's deputy chief of staff.

[88][89] Soon after ending his campaign for mayor, Johnson moved to start a government relations consulting firm, Cojo Strategies, which began advising to a subsidiary of the Brooklyn Nets and the Central Park Conservancy.

[90] An Israeli tech firm hired Johnson as its United States government relations advisor, with a focus on New York.

[91] Johnson represented Saferwatch, a company developing a "panic button" app who sought to provide it to schools in the City of New York.

Saferwatch ceased being represented by Johnson in early 2024, and hired the government relations services of Terence Banks, the New York City Schools chancellor's brother.