Editor's note: Julian E. Zelizer is a professor of history and public affairs at Princeton University. He is the author of "Jimmy Carter," published by Times Books, and editor of a book assessing former President George W. Bush's administration, published by Princeton University Press.
Princeton, New Jersey (CNN) -- Suddenly no one is talking about Congress as the "broken branch" of government any more.
Conservatives are complaining that the 111th Congress did too much, while liberals are boasting about all that was accomplished.
Within the span of a month, the media discussion shifted from the chronic complaints about partisan gridlock to, lo and behold, claims that this was the most productive Congress since the mid-1960s. Everything seems just fine on Capitol Hill.
The recent legislative success will create problems for Senate Democrats when they push for filibuster reform as soon as Congress reconvenes this week. The details of the upcoming reform package are still unknown. Based on most reports, the reforms are rather mild in that they don't attempt to lower the number of senators required to end a filibuster (currently 60).
Rather, the reforms are expected to focus on increasing the cost of launching a filibuster. Senators would actually have to stand on the floor, Mr. Smith style, and the Senate would be unable to work on other business while a filibuster is taking place. The reforms will probably attempt to end secretive practices such as the "hold," which enables senators to anonymously block legislation from being debated.
Other reforms being discussed include narrowing the scope of votes that can be filibustered and reducing the length of debate after senators have successfully voted for cloture.
Some opponents of reform will certainly ask, given the recent coverage of the historic 111th Congress, whether procedural changes are really needed. Shouldn't senators just leave things alone?
The answer is no. The past three decades of congressional history have been marked by a filibuster frenzy. The most striking characteristic of the modern Senate is that members now assume that 60 votes are required to pass almost any legislation.
Despite all the criticism that has been made about the Senate in previous periods, simple majorities were sufficient to pass most legislation for much of the institution's history. Filibusters have taken place since 1841, but they had been used only rarely before the 1970s.
Whereas senators once reserved filibusters for big issues such as civil rights, now they are willing to filibuster, or threaten to filibuster, everything that comes their way. In short, the filibuster has become a normalized tool of partisan conflict.
Political scientist Eric Schickler found that there was an explosion of obstructionism that occurred in the 1970s and 1980s as senators used filibusters as well as holds.
According to senate.gov, history was made during the 111th Congress when Majority Leader Harry Reid attempted to break more filibusters than in any other recorded year (136, compared with 68 in the 109th Congress or 82 in the 104th). These figures don't capture the full scope of obstruction, as they only record those instances where the Senate majority actually tried to stop the debate.
Many routine decisions were delayed and obstructed because the minority could rely on the filibuster and were willing to use the procedure with high frequency.
Legislation such as the food safety bill, the 9/11 responders bill and the extension of unemployment benefits during a struggling economy historically would not been the kind of proposals to be obstructed. But in this day and age, Republicans were able to extract a huge concession in exchange for unemployment benefits -- the extension of all of the Bush-era tax cuts for two more years.
Other legislation that seemed to have majority support in both chambers languished, such as the DREAM Act and immigration reform.
The nomination process has been stifled as a result of filibusters. This is one issue on which Democrats and Republicans can agree. President Obama has made 28 recess appointments, more than President George W. Bush at this point in his tenure. These are appointments that the president makes while the Senate is in recess, typically done because the White House knows the appointments would be held up in Congress.
Even with the legislation that passed, the new normal of a supermajority requirement for every bill has a profound effect on the quality of the final legislation.
While many commentators have focused on the volume of legislation that passed since President Obama became president, the more important question is how durable the programs will be and whether they will be undermined in the coming years.
The filibuster allowed the Senate minority to substantially weaken and diminish legislation that made it through the chamber. At the height of the Great Recession, the administration significantly scaled back its stimulus bill to levels that many economists warned would be insufficient to really boost the economy.
Equally important, Senate Republicans and a handful of conservative Democrats were able to force major concessions on the health care bill. That included the weakening of cost controls and the decision to have states run the health care exchanges, making the program politically fragile and raising immense challenges for implementation that were avoidable with a stronger bill.
Importantly, the filibuster has usually not produced bipartisan agreement. The concessions have been a one-way street. What we saw during the 111th Congress was that the filibuster allowed the minority to force concessions but then those in the minority often have not been willing to provide a vote in favor of the bill once the changes are made.
Moreover, it is hasty to read too much into the lame-duck session and start singing a bipartisan kumbaya.
After all, the major moments of bipartisan agreement involved the tax cut/unemployment compensation deal, in which the administration wound up paying a huge price that will greatly worsen the long-term deficit, all without a strong stimulative effect. It will also create political opportunities for the GOP to attack the president in the next two years for being fiscally irresponsible.
The case for filibuster reform remains strong.
At a minimum, the Senate should pass reforms that will make the filibuster, and those who filibuster, more visible to the public. But senators must also consider lowering the number of senators required to end the filibuster to 50 or at least to some number lower than the current 60. This is the reform that would have the greatest effect.
Both parties have an interest in creating a system where a supermajority does not remain the norm for passing all significant legislation. Reforming the filibuster would also weaken one of the most powerful tools in partisan combat.
The congressional system creates more than enough opportunities to slow down the process and enable the minority to influence decisions. The rules of the filibuster can and have been changed, just as occurred in 1975 when senators lowered the number required for cloture from two-thirds of those present and voting (up to 67) to three-fifths of the Senate (60).
Both parties should cede some of their power -- Republicans the power they have and Democrats the power they would would want should they lose control of the Senate -- to improve the legislative process for generations to come. That would be historic.
The opinions expressed in this commentary are solely those of Julian E. Zelizer.