From Foxnews.com:
“The government can regulate discrimination in employment or against customers, but what the government cannot do is to punish someone for their words,” said Adam Schwartz, senior attorney for the American Civil Liberties Union of Illinois. “When an alderman refuses to allow a business to open because its owner has expressed a viewpoint the government disagrees with, the government is practicing viewpoint discrimination.”
The ACLU “strongly supports” same-sex marriage, Schwartz said, but noted that if a government can exclude a business for being against same-sex marriage, it can also exclude a business for being in support of same-sex marriage.
“But we also support the First Amendment,” he said. “We don’ think the government should exclude Chick-fil-A because of the anti-LGBT message. We believe this is clear cut.”
Seems correct to me.