My representative, who is generally a pretty progressive guy, is on this list. A local journalist asked about his vote, and the statement from his office was that the congressman is waiting for a classified briefing on the Iran strikes to help determine whether the president broke the law.
I know that we live in a world where we expect not only a 24-hour news cycle, but 24-hour resolutions to all issues. Having a solid argument and proper evidence for impeachment is the sort of thing that moves more slowly than we would like.
American Atheists is an organization that will happily take dues and send you a membership card in return.