Declare atheism a religion ...and shut up them up! Make them practice what they preach!
Atheism is a religion.
It is their belief system relating to the existence (or in their case, the nonexistence) of a divine creator.
The fact that the courts routinely issue edicts favoring their belief-system (religion) over the belief-systems of Christians and Jews (for the most part, they only attack Christians and Jews) is unconstitutional.
Good luck with them shutting up or practicing what they preach, however.
(Full disclosure: I consider myself agnostic, bordering on atheism. My opinion though is that Judeo-Christian values are great, moral values and are what this country was founded upon. I see, and oppose, the militant atheist religion's attacks on those religions.)
In 1960, the US Supreme Court, in the Torcaso case, decalared secular humanism not only atheistic but also a religion in the same sense that Buddhism and Taoism are religions. Humanism, by implication, was granted status as a worldview complete with its own theology.
"Among religions in this country...[is]...secular humanism"
Supreme Court Justice Black, 1960