FILE - In this March 10, 2014, file photo, Masterpiece Cakeshop owner Jack Phillips decorates a cake inside his store in Lakewood, Colo. Salt Lake City Mayor Jackie Biskupski is among mayors and cities across the country urging the U.S. Supreme Court to bar a Colorado cake maker Phillips from "status-based discrimination" against a same-sex couple.
Brennan Linsley, Associated Press

SALT LAKE CITY — Salt Lake City Mayor Jackie Biskupski is among mayors and cities across the country urging the U.S. Supreme Court to bar a Colorado cake maker from "status-based discrimination" against a same-sex couple.

Biskupski signed on to a friend-of-the-court, or amicus, brief filed Monday with 80 mayors and 70 counties, cities and towns siding with the Colorado Civil Rights Commission.

The municipalities in the brief have adopted a wide range of local laws and policies prohibiting discrimination on the basis of various characteristics, such as race, religion, sex, sexual orientation and gender identity.

They argue that cohesiveness and inclusiveness depend on their ability to insist that everyone, regardless of their beliefs, values and private conduct, treat each other equally and with respect in employment, housing, public accommodations and other areas.

"Discrimination against LGBTQ people — whether the loss of a job, eviction from a home, or rejection by a business — demeans them as individuals and affects our communities as a whole, fostering an environment of exclusion where not all are entitled to respect," according to the court filing.

Masterpiece Cakeshop owner Jack Phillips refused to create a cake for the wedding reception of a gay couple who were planning to marry in Massachusetts, citing his religious beliefs. The couple, Charlie Craig and David Mullins, pursued discrimination charges and won before Colorado's civil rights board and in the courts. Phillips appealed, and the Supreme Court agreed in June to hear the case.

Biskupski, a Democrat, isn't the only Utah politician to weigh in on the case, though the others have taken the opposite side.

Sen. Mike Lee, R-Utah, Republican state senators and GOP Attorney General Sean Reyes have joined briefs on behalf the cake shop.

Lee has said it is not a public accommodations case. He called it a "compelled speech" case because the couple asked Phillips to use his talents to make a specialty cake to carry a message with which he disagrees.

The mayors' brief argues that although a baker may use creative talents in designing a wedding cake, a cake created by a business that holds itself out to the public is not the baker’s speech. There is no plausible basis to conclude that the cake shop would have expressed any message of its own by selling a wedding cake to Craig and Mullins, according to the brief.