Climate Bill 2.0 on Hold

Senator Graham has announced that he’s withdrawing from the effort to pass the bill that he helped to draft, because he’s irked that the Administration is pressing forward on immigration reform.  I’m struggling a bit to understand this.  The charitable explanation is that he’s trying to pressure the administration into giving the climate bill priority.  The uncharitable explanations are that he’s caving in to pressure from party leaders, or that he’s just having a hissy fit.