For many years, I have marveled at the discipline displayed by the Republican Party. Far more than their Democratic counterparts, Republicans generally remain on message, strictly adhering to their talking points. They even have pollsters to advise them on what particular words and phrases to use to persuade the public. Moreover, it makes no difference to Republicans whether their message is true or correct or even reasonable. They have long subscribed to Hitler’s theory that if “you’re going to tell a lie, tell a big lie, and if you tell it often enough and say it in a loud enough voice, some people are going to believe you.” The party is aided and abetted by Fox News, the conservative blogosphere, and talk radio. Inside this echo chamber, global warming is a hoax, tax cuts on the wealthy spur economic growth, and voter fraud is an epidemic. As a result of this masterful propaganda, the Republicans have dictated the terms of the political narrative in this country for decades. They have also convinced generations of Americans to vote against their own interests.

Nowhere is Republican discipline more manifest than with respect to the Taxpayer Protection Pledge, which was created by Grover Norquist of Americans for Tax Reform. Since its inception in 1986, the pledge has become de rigeur for Republicans seeking office. Signatories agree in writing to: “ONE, oppose any and all efforts to increase the marginal income tax rate for individuals and business; and TWO, oppose any net reduction or elimination of deductions and credits, unless matched dollar for dollar by further reducing tax rates.” As of November 2012, nearly every Republican in Congress-238 of 242 House Republicans and 41 out of 47 Senate Republicans-has signed the pledge. It has been an enduring monument to conservative solidarity.

Until recently, violating the pledge was considered an act of perfidy. Indeed, no Republican in Congress has voted for a tax increase since 1990. However, after the November 2012 elections, there are, for the first time, signs of cracks in the foundation. A handful of Republicans, including Senator Lindsey Graham, Senator Saxby Chambliss and Representative Peter King, have indicated that they would violate the pledge and increase taxes in order to avoid the impending fiscal cliff. Norquist was quick to remind these lawmakers of the potential consequences of their decision, invoking the name of his most famous victim-President George H.W. Bush-who lost his re-election bid in 1992 after reneging on his promise not to raise taxes. But even taking into account the recent defections, 98-percent of Republicans still swear fealty to the pledge. They remain a formidable obstacle to any attempt to raise taxes.

Whatever you may think of the pledge, and a compelling case can be made for its absurdity, it does serve its purpose. The pledge keeps the Republican Party unified around a core principle.

There is no such tie that binds the Democrats. The Democratic Party maintains a diverse and, at times, tenuous coalition. It consists of, among other factions, organized labor, racial and ethnic minorities, single women, and the LGBT community. It is susceptible to wedge issues, which the Republicans have used effectively over the years to alienate and peel off certain segments of the coalition. And unlike Republicans, who systematically purge moderates, the Democrats don’t demand ideological purity within their ranks. There are progressives, centrists, and Blue Dogs, all of whom have to coexist under the same tent.

Because of the internal dynamics of the party and its broad constituency, the Democrats are often at an inherent disadvantage when negotiating with Republicans. In the event of a stalemate, it always seems like it is just a matter of time before the Democrats cave. It’s not that Democrats lack the courage of their convictions in these negotiations. Rather, it is exceedingly difficult to keep their fractious coalition intact, particularly when addressing divisive issues like abortion, gun control or gay rights. Republicans, on the other hand, are not only incredibly unified (over 360 filibusters in the Senate over the last six years), but are also comfortable with brinksmanship as a strategy. They are willing to shutdown the government or have it default on its credit obligations to get what they want. These tactics are dubious, but it is hard to argue with results.

Imagine, however, if there were a bedrock issue or set of issues that was so sacrosanct to Democrats, that they would be willing to lay down the gauntlet. What if there were a dominant orthodoxy that galvanized all members of the party across the political spectrum? This is, of course, entirely hypothetical (and completely impractical), but worth considering. For example, if Democrats pledged to never cut entitlements or cap military spending at a certain percentage of GDP, the fiscal cliff negotiations would take on a whole new posture. What if there were a singular influential figure or potentate that appeared regularly on MSNBC with thinly veiled threats of retaliation against any Democrat that dared to violate such a pledge. The nature of our politics would change exponentially.

It is a sad testament to our political system that certain elected officials are more accountable to a pledge than they are to voters. But, be that as it may, the pledge is a useful tool for the Republicans. And until the high-minded Democrats are able to find an unifying rallying cry, they will continue to bring a knife to a gunfight.