Mark — one minor correction to your post. You write that “senators sued in the ’90s to stop a D.C. voting bill, and lost for lack of standing.”
That lawsuit actually wasn’t over a D.C. voting bill; it was about a different statute (the 1996 line-item-veto law) that had a provision purporting to give legislators standing to sue. Von Spakovsky’s argument was that even if the D.C. bill passes with a similar provision, the courts wouldn’t have to respect it, because they haven’t in the past.