The Republican base is used to being disappointed by its leaders. Time and again, when the chips are down, whether it be in the Senate or the House, a small group of Republican lawmakers join with Democrats to advance “must-pass legislation” without extracting any concessions.

Over the years it has become such a regular occurrence that, in general, the Republican base assumes that its politicians will cave on tough votes, especially when it comes to funding the government and avoiding the shutdown. Omnibus bills, continuing resolutions, the lot, would pass with unified Democratic support and enough Republican support to get it over the finish line.