I believe the latter is the case. None of the gang of seven are part of the GOP leadership in the Senate and more often than they should, vote with the Dems. This is their way of asserting their limited power in much the same way that Jeffords became disaffected. McCain should remember that he holds a committee chairmanship because the GOP is in power and not the minority. These guys are not team players.
Nail, head, you just hit it. :-)
Why does Warner chair the Armed Services Committee ?