One of my favorite one-liners: “Behind every great man is a constantly amazed woman.” That statement somewhat applies to a show playing through Dec. 10 at the Steppenwolf Theatre. “POTUS: Or, Behind Every Great Dumbass Are Seven Women Trying to Keep Him Alive” by Selina Fillinger is a bawdy and irreverent look at sex, politics and the women in charge of the man in charge of the free world.If you are going to appreciate this play, you have to get past its first and last scenes, which both feature some profane language. I …