Just like they were totally going to vote down Tillerson, right?
I'd argue this is different. Also, I can imagine Collins, Toomey, Murkowski, Portman, etc being against this as well. This is an issue that legitimately divides the Republican Party.
As I was saying in another thread just yesterday: Yes, basically the entire GOP caucus in the Senate is going along with Trump on personnel. But that's normal. Senators always back a president from their own party on personnel. Once we go from personnel to actual policy though, that's where presidents will face some resistance from their own party. It's already playing out on health care, and it'll play out on immigration and other issues.