Ron Johnson is the leadership representative, signaling support, since McConnell and Cornyn are up for reelection and are pretending to be conservative.
This is how things are done.
“.....The current dynamic in the Senate as it relates to the Ryan-Murray whip count represents the consummate opportunity for leadership from the top. Democrats have not fully secured 60 votes to pass this awful deal. If McConnell and Cornyn really felt the way we do about this bill, they would launch a counter-whip operation to convince members on the fence to vote no. Unfortunately, they have reverted to the ‘hope yes, vote no’ mode. They really want the bill to pass, but they are too scared of their primary challengers. Consequently, they are sitting back and allowing Democrats to pick off members of their conference one-by-one.....”
http://www.redstate.com/2013/12/16/hope-yes-vote-no-is-not-a-winning-equation/