"tu quoque" (party A did this so that makes it right for party B) is not a valid argument. If it was unconstitutional then, it's still unconstitutional now (eve

"tu quoque" (party A did this so that makes it right for party B) is not a valid argument. If it was unconstitutional then, it's still unconstitutional now (even if it's now a tradition). (Cf. Gephardt Rule)