I don't know that that's true, Taz. We're the
least trusted demographic, but not necessarily the
most discriminated against, primarily because the difference that sets us apart from the theistic majority isn't readily visible.
You won't often find an atheist receiving fewer opportunities for employment, for example, or getting paid less than peers. You
will find women and racial minorities and sexual orientations and transgendered individuals who have those problems.
Granted, we feel discriminated against because of the overwhelming pressure from theists who want to push all of their beliefs into the public forum on the public dime, like posting the Ten Commandments in courthouses, claiming the US is a "Christian Nation," and so on. Atheists also get some pretty harsh resistance sometimes in the armed forces.
But I'm a white male atheist. I can pass for a WASP without even trying, and in fact that's what most people just
assume I am. The KKK hates Atheists (and Jews and homosexuals and of course blacks and just about everyone else who isn't a WASP...), but I could walk right past a rally and never hear anything directed at me. A black person walking by the same rally would have a...different experience.
That the majority of people think we're all going to their imagined "hell" could be considered analogous to widespread acceptance of a slur against a minority...but the fact that we can;t be immediately recognized as Atheists means that it's a
generalized oppression, rather than the very
specific nastiness that various others have to face.
On what are you basing the claim that we receive
more discrimination than any other minority group?