While serving in his second term in 1990, Johnson was selected by the council to fill the vacancy left by outgoing mayor Terry Goddard, who had resigned his office in order to run for governor.

Johnson ran against Goddard who was making his second bid in 1994, but they both lost to another primary candidate, popular supermarket owner Eddie Basha.

The win shocked pundits like Pat Murphy, Arizona Republic columnists, and many who believed Johnson was too young and was in the wrong party for the district.

[6] As a councilperson, he developed a “specific plan” to improve the area and activated a citizens committee to create buy in.

[10] As a councilperson, Johnson focused on economic development[11] and the environment, trying to find the right balance between business and conservation.

Among other issues, Johnson fought with oil company lobbyists[12][13] and became the primary lead[14] in the state to adopt an Ethanol ethical-based fuel.

[15] Johnson's goal was to bring the state air quality standards into compliance by reducing carbon monoxide.

[18] Johnson took the lead on the local effort to reduce Chlorofluorocarbons (CFCs) that were endangering the world's ozone protective shield.

[19] Johnson also called for the planting of more than a million trees in the city to help lower carbon monoxide and cool the local environment.

While this took significant amounts of his time during his first two years as mayor, Johnson had a robust city agenda and was actively engaged in decisions surrounding the environment, education,[28][29] social justice, ethics, and crime.

The Phoenix economy, heavily dependent on real estate, began to falter in 1989, six months before Johnson took office, after the collapse of the savings and loan institutions.

This crisis caused deep deficiencies in revenues for the City of Phoenix and significant changes in the social, business, and political landscape of the state.

[36][circular reference] In response, the Federal Reserve created a restrictive monetary policy contributing to an economic recession.

[55] Johnson built relations with other national economic interests[56] that assisted in financing the basketball arena and securing funding for the Japanese Friendship Garden at Margaret T. Hance Park.

He held open forums to talk about race and equality, appointed record numbers of women and minorities to boards and pushed to employ more black officers in public safety.

[72] The Johnson Council passed the Human Rights Ordinance that prohibited discrimination against employees based on sexual orientation.

[79] Johnson and Chicago Mayor Richard M. Daley also worked with the Clinton Administration and then-Attorney General Janet Reno to stop law enforcement agencies from selling seized weapons to gun dealers and organized support from cities across the nation.

[88] Johnson also called for individual responsibility by taking part in block-watch[89] and requiring parents to participate in community service work when their kids broke curfew.

One of the key issues was protecting Florida wetlands and swapping “alligator alley” for a prime piece of property in downtown Phoenix called the Indian School Park.

[93] He was a leader in the community to force a deal with the developer who purchased the property and intended to turn it into a very dense commercial project.

[96][97] After a heated fight, Johnson was able to land a significant portion of the Indian School Park in trade for a commercial property in downtown Phoenix.

[105] Johnson ran for governor of Arizona in 1994, and though unsuccessful, won the endorsements of both of the state's major daily newspapers.

While both Fife Symington and Johnson were bitter rivals in politics, they began to form a partnership after office, working together on several initiatives.

This allowed groups like the Koch Brothers[107] and other large funding sources to hide from the public contributions made to candidates and causes.

[108] Johnson was a national leader focused on empowering independents in the electoral process, stopping legislative efforts from diminishing popular votes,[109] and trying to remove dark money from political campaigns.

In 2016, he ran the effort to open up the elections for independents to participate[115] and to force dark money founders to disclose their contributions.

Johnson's largest effort has been in Redirect Health, a company focused on low wage workers and disrupting the current healthcare system.

Johnson, in several publications, points out that almost 1/3 of the cost of healthcare could be eliminated by cutting administration, fraud, abuse, and overcharging.

[124] Johnson advocates that the free-market approach is the only way to truly cut costs, enabling employers to buy their healthcare directly, bypassing large networks.

[130] His clear passion is trying to find a private-sector solution for lowering the cost of healthcare to give it greater accessibility to the working poor.