It's like Obama. He could have gone far to the left, or gone really bold (he really didn't do either). His two signature achievements -- health care and the stimulus -- became, under the glare of the lights, half-measures. Time will tell if they mature into something more significant.
In 1994, Republicans had no institutional memory of being in power. That allowed them to be bolder in their promises and convictions. Arguably, it also led to their excesses, such as the government shutdown of 1995. Voters will expect Republicans in the House to pass legislation that Obama could theoretically sign. Voters will expect new ideas, especially for the struggling middle class. If they get none -- if they get the Pledge -- the party will have wasted another chance to actually move the country to the right through policy, rather than simply delaying an inevitable creep to the left. The House GOP doesn't get the vision thing. Maybe they don't need to to win an election. But conservative independents aren't necessarily going to be satisfied with the same old, same old. And neither will a general election audience.