All his colleagues, D or R, understand this. It allows them all to posture publicly for their respective constituents while speaking in their other, private voice in the back room. The goal of this two-voice system is the re-election of incumbents, and nothing else.
They all understand this of each other. It's what the word "comity" really means.
If you heard the interview, he gave himself no way out. Graham is in this thing all the way.