CHICAGO (CBS) — As the US Supreme Court hears arguments on whether a business has a constitutional right to deny service to someone based on their beliefs, the ACLU and Chicago businesses are taking part in a day of action they are calling “Open To All.”

A sign at Alliance Bakery, located on the 1700 block of West Division, reads “Open To All,” in response to a Supreme Court case in which a bakery refused to make a wedding cake for a gay couple.

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“I just don’t feel it’s right, you know,” said owner, Peter Rios. “We provide a service. We kind of in a way are in the entertainment business where we need to bring these beautiful cakes for folks who are having events, parties, weddings, etc. We need to include everybody.”

Rios said the bakery may get a little edgy at times with political messages on their cookies, but he said, turning someone away, refusing their business because they are gay is wrong.

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“We never discriminated since day one. When I first heard the news that came out I was actually kind of appalled and I just don’t feel it is right,” he said.

Ghirlandi Guidetti, with the ACLU of Illinois said, society decided a long time ago that when you open a business to the public, “you need to serve everyone, and serve everyone equally.

“You can’t turn someone away just because of who they are. It’s a no-brainer.”

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Dozens of local businesses are taking part in the “Open To All” day of action.