Following her education, she joined the Illinois Association of Park Districts' (IAPD) Board of Trustees in 2015 and served two years as vice chair and one year as chair-elect.[3]
She was appointed to the Illinois Senate on October 11, 2020, succeeding Terry Link.[4][5] Johnson is the first African-American state senator to represent Lake County, Illinois.[6] She has continued to serve on the Buffalo Grove Park Board following her appointment until the end of her board term.[7]
As of July 2022, Senator Johnson is a member of the following Illinois Senate committees:[8]
Appropriations - Agriculture, Environment & Energy Committee (SAPP-SAAE)
Appropriations - Human Services Committee (SAPP-SAHS)
Behavioral and Mental Health Committee (SBMH)
Commerce Committee (SCOM)
Environment and Conservation Committee (SNVR)
Ethics Committee (SETH)
Public Safety Committee (SPUB)
Redistricting - Lake & McHenry Counties (SRED-SRLM)