As a high school student, she entered a speaking contest and won the prize of scholarship of her choice, in which she chose Howard University in Washington D.C.. One instance that was a major influence on her life was on a Sunday morning when she was in church with white friends in college and she was escorted out by ushers.

Both she and her husband became active locally in the National Association for the Advancement of Colored People (NAACP) in support of a city redistricting referendum (there were at that time no black members of Milwaukee's Common Council).

Phillips frequently participated in nonviolent civil rights protests against discrimination in housing, education, and employment during the 1960s.

She lost her bid for reelection to the bench to a white candidate who made an issue of her involvement in protests and civil rights activities.

Incumbent Democratic Secretary of State Doug La Follette ran unsuccessfully for Lieutenant Governor and Phillips won the highly fractured nine-candidate Democratic primary with just 25.6%, though she did finish more than 10% ahead of the second-place candidate, Native American advocate and scholar Ada Deer.

A lifelong Democrat, she was also the first black person to be elected as a member of the National Committee of either of the major U.S. political parties.

After leaving office, Phillips remained active in the community, serving on the boards of the Wisconsin Conservatory of Music and America's Black Holocaust Museum.

[8] She chaired the successful congressional campaign of Gwen Moore, Wisconsin's first African-American and Milwaukee's first female member of the United States House of Representatives.

[14] That statue was unveiled on July 27, 2024; it is the first outdoor sculpture on the capitol grounds of any American state of an African-American woman.