Bunning's stated rationale was that the bill did not follow paygo, the principle Democrats want reinstated in spending that each spending increase will be paid for in a spending cut or tax increase. Bunning said the 30 day extension would cost $10 billion.
However, as a Senate colleague pointed out in last night's debate, Bunning was unconcerned about paygo during the Bush years when he voted for two unfunded wars and all the deficit spending that W pushed through. If the Republican party wants to avoid the label of the party that hates the poor, Bunning did them no favors.