When Republican moderates mucked up the budget-reconciliation bill, some commentators expressed shock at the sudden disappearance of party discipline. More shocking is that Republicans have been able to maintain such unity for so many years. The House is neither a parliament nor an extension of the president’s will and will not be governed as such for long.

During Bush’s first term, House Republicans excelled at “getting to 218,” but in the past few months factions of Republicans have been taking turns playing a new game: “getting to 14.”

Two hundred eighteen is, of course, a bare majority of the 435-member House. In the current House, with 231 Republicans, 14 is the magic number of Republicans that have to defect to prevent the assembly of a majority. That means that less than 10 percent of the caucus can hold a bill hostage.

So when 25 moderates united to insist that the Arctic National Wildlife Refuge (ANWR) drilling provision be removed from the reconciliation bill, the leadership agreed in order to pass the bill. Republican leaders figured that in conference they could restore the ANWR provision, which is in the Senate bill, and that they might win a floor vote on final passage. But the moderates’ stand led to a counter-reaction in other, more conservative parts of the caucus, and leaders, who were counting on almost no Democratic votes, found themselves unable to pass the bill.

All of these machinations come on the heels of other revolts over the summer, mostly from conservative members, who united in favor of spending cuts and forced the leadership in a more fiscally frugal direction.

These developments are not surprising because the Republican margin in the House is slim. Consider that from 1959 until 1994 Democrats never had fewer than 242 members in their caucus and several times exceeded 290. But more than the thin margins, the nature of our institutions leads to somewhat fractured majorities. It is the Bush first term that is the outlier, an extraordinary period of party and cross-branch unity that will be hard to duplicate in the future.

When President Bush took office in 2001, it was the first time in nearly 50 years that a Republican president had a Republican majority in Congress. He quickly settled into a regular pattern of dealing with Congress. Bush would propose legislation, the House would only slightly modify the president’s approach and pass it with nearly unanimous Republican support, and the real bargaining would then begin in the Senate, where a deal would be cut with a few moderate Democrats.

This arrangement worked well for the president and for the Republican majority as a whole. But, with the exception of a few key members, Ways and Means Committee Chairman Bill Thomas, for example, on the tax bills, most Republican members were just a rubber stamp for the final product, and House Democrats were largely irrelevant.

Maintaining this system requires a strong president, an active agenda, a record of winning and a continued submergence of congressional egos to a larger good. Bush’s declining popularity in his second term, the dearth of significant victories and his inability to set the agenda have returned Congress to its more natural state. Once the genie is out of the bottle, it is hard to put back in.

This is not to say that Bush could not regain some of his stature and that there won’t be collaboration between the president and congressional Republicans, but it will more often be on Congress’s terms, and congressional majorities will have to be assembled the old-fashioned way, piece by piece, rather than under the banner of party unity.

Fortier is a research fellow at the American Enterprise Institute.