From NBC's Ken Strickland
As many as EIGHT back-to-back votes are happening now on the Senate floor in relation to the health-care bill, but don't expect any drama. 

The Democrats should have the votes to beat back any Republican efforts.

Currently they are voting on Sen. John Ensign's (R-NV) amendment challenging the constitutionality of the health-care bill. (Olympia Snowe, by the way, just voted aye.)

We'll keep you posted.