The American Civil Liberties Union (ACLU) is making headlines for defending the rights of a Christian conservative organization after the group was denied permission to advertise on buses operated by the Washington Metropolitan Area Transit Authority (WMATA).

WallBuilders Presentations is a Christian organization that advocates for educating Americans about their history and the role of religion in the founding fathers’ efforts to establish the nation. The organization previously requested to advertise on buses in Washington D.C., but its request was denied by WMATA because it was a violation of its advertising guidelines.

According to WMATA, advertisements are prohibited that “intend to influence members of the public regarding an issue on which there are varying opinions.” The transit authority also restricts advertisements that are related to religious practices or beliefs.

The ACLU argues that WMATA’s advertising guidelines violate the First Amendment. The organization emphasizes that the First Amendment does not play favorites and ensures that all voices, regardless of their message, should have the right to be heard in public forums.

The ACLU also pointed out the inconsistency in WMATA’s past approvals of ads with religious content, such as The Book of Mormon musical, which many interpreted as a mockery of the Mormon Church.

“The case against WMATA is a critical reminder of what’s at stake when government entities exercise selective censorship. The First Amendment doesn’t play favorites; it ensures that all voices, regardless of their message, have the right to be heard,” said Arthur Spitzer, senior counsel at the ACLU-D.C. “The ACLU defends these suits, regardless of whether it agrees with the underlying message, because it believes in the speaker’s right to express it. The government cannot arbitrarily decide which voices to silence in public forums.”

The ACLU has traditionally been associated with supporting liberal causes, making its recent defense of the constitutional rights of conservative and religious groups all the more shocking.