After the Senate passed a bill to extend some of the tax hikes that are scheduled to take effect at the beginning of the year, the action has moved to the House of Representatives, where Republicans are warning that they might reject the Senate proposal.
One aspect of the fight that I don't think has gotten as much attention as it deserves is how the negotiations are shaped by recent procedural changes. Traditionally, the House has had relatively weak party discipline. While the Speaker would generally try to enact legislation that was popular within his own caucus, this wasn't an iron rule. If circumstances dictated it—for example, if he was negotiating with a president or Senate leadership from the opposite party—the Speaker might allow legislation to come to the floor that had weak support within his own party, relying on a mix of Democratic and Republican votes to pass it.
As Matt Yglesias has pointed out, Speaker Dennis Hastert established a "majority of the majority" rule, in which the leadership wouldn't bring legislation to the floor unless it enjoyed the support of the majority of Republicans. John Boehner adopted an even stronger version of the same rule.
This arrangement tends to shift policymaking toward the right (when Republicans are in the majority) because it means that to get legislation through the House you need the support of the median Republican rather than the median House member. But a proposal that enjoys the support of the median Republican is likely to be too far to the right for many Democrats to support. That's not a problem if the GOP majority caucus is unified, but if the majority is divided, the "majority of the majority" rule can mean that it's mathematically impossible to craft legislation that is supported by a majority of both the GOP caucus and the full House.
In parliamentary systems, this is often dealt with through the mechanism of confidence votes. The leader of the parliamentary majority will declare that a particular bill is considered a "vote of confidence," meaning that if it fails to get a majority of the house, then parliament will get dissolved and new elections held. That puts pressure on dissident members of the majority to toe the party line. They'll only vote no if they're sufficiently unhappy with the current party leadership that they're willing to bring down the government.
We don't have a parliamentary system, and the speaker doesn't have the power to call new elections. Under our non-parliamentary system, the party leadership has less leverage to pressure rank-and-file members of the caucus. The result is episodes like last month's "Plan B" fiasco, where Speaker Boehner tried and failed to pass an official Republican solution to the fiscal cliff. Democrats were unified against the bill, which they viewed as too conservative. Yet many Republicans viewed it as not conservative enough, and Boehner didn't have any way to force them to support it.
In short, John Boehner has committed himself to a set of principles for operating the House that makes the body fundamentally dysfunctional. A functional legislative body either needs a mechanism for the majority leader to get members of his caucus to toe the party line, or he needs the ability to "reach across the aisle" to get the votes he needs from the minority. John Boehner lacks the former, and by ruling out the latter he's effectively painted himself into a corner where he might not be able to get any piece of "fiscal cliff" legislation passed by the full House of Representatives.
