Pet name for the Republican Leader in the U.S. Senate, Mitch McConnell of Kentucky.
"Miss" highlights the fact that McConnell is very widely rumored to be America's most prominent closeted homosexual.
Comment on Wonkette: "Mitch cries every time a good staffer pulls out."
Woman: Why are they saying that? What can it mean?
Man: I think it was a jibe at 'Miss McConnell'?
Woman: Why are you calling my dear leader in the Senate 'Miss'?
Man: Because he's a closeted homo.
Man: Yup, just imagine what else 'Miss McConnell' is lying to you about.