The DOJ definitely won't get involved, as there was no overt action taken and the attempted extortion charge would be so politically hot that they would fear a backlash. However, you should definitely send this or a similar letter to the Senate Ethics Committee chairman (George Voinovich) and request that each of these Senators be formally censured (expulsion is probably too much to expect).
I'll be sure to add the Ethics Committee chair to the cc list. Should I also include the President Pro Tempore and Sergeant at Arms?