Yes, Rule 23:
Senate Rule 23
Senate Rule 23. Committee not to be absent. Members of a committee, except a conference committee, may not be absent by reason of their appointment during the sitting of the senate, without special leave.
[am. 2001 S.Res. 2] emphasis mine
I’m a literal type of gal, and “may not” means you absolutely, positively cannot be absent–without taking special leave (maybe they could get a doctor’s note). Here are the past and future committee schedules for February and March 2011.
Will tone-deaf, taxpayer-betraying Democrats Tim Carpenter, Spencer Coggs, Tomothy Cullen, Jon Erpenbach, Dave Hansen, Jim Holperin, Robert Jauch, Chris Larson, Julie Lassa, Mark Miller, Fred Risser, Lena Taylor, Kathleen Vinehout, and Robert Wirch abide by the Senate rules that they adopted in January 2011. Or will they continue to hold their positions in contempt and be cowards?