Mitch McConnell: The Filibuster Plays a Crucial Role in Our Constitutional Order

“You’ll regret this, and you may regret this a lot sooner than you think.”

That was my warning to Senate Democrats in November 2013. Their leader, Harry Reid, had just persuaded them to trample longstanding Senate rules and precedents. Now that some Democrats are proposing further radical changes to the Senate’s functioning, it is instructive to recall what happened next.

To confirm more of President Barack Obama’s controversial nominees, Democrats took two radical steps. First, since the nominees had proved unable to earn the 60 votes necessary to overcome a filibuster, Democrats sought to change Senate rules so that ending debate on most nominations would require only a simple majority. Second, lacking the two-thirds supermajority needed to change the rules normally, Democrats decided to short-circuit standard procedure and muscle through the new rule with a simple majority as well — the first use of the infamous “nuclear option.”

Republicans opposed both moves on principle. Strong minority rights have always been the Senate’s distinguishing feature. But when appeals to principle fell on deaf ears, I tried a practical argument. The political winds shift often, I reminded my Democratic friends. I doubted they’d like their new rules when the shoe was on the other foot.

Unfortunately, Senate Democrats bought what Senator Reid was selling — but buyer’s remorse arrived with lightning speed. Just one year later, Republicans retook the majority. Two years after that, Americans elected President Trump. In 2017, we took the Reid precedent to its logical conclusion, covering all nominations up to and including the Supreme Court.

So this is the legacy of the procedural avalanche Democrats set off: Justice Neil Gorsuch, Justice Brett Kavanaugh and 43 new lifetime circuit judges — the most ever at this point in a presidency. The consequences of taking Senator Reid’s advice will haunt liberals for decades.

A number of Democrats publicly regret their 2013 vote. One calls it “probably the biggest mistake I ever made.” Nevertheless, the far left now wants Democrats to touch the hot stove yet again. This time, they want to erase the Senate’s 60-vote threshold to end debate on legislation.

A Democratic assault on the legislative filibuster would make the nomination fights look like child’s play. That’s because systematically filibustering nominees was not an old tradition but a modern phenomenon, pioneered in 2003 by Democrats who opposed President George W. Bush. When Republicans followed suit and held up a handful of Obama nominees the same way, Democrats could not stomach their own medicine and began a “nuclear” exchange that Republicans had to end.

The back-and-forth was regrettable, but the silver lining is that the failed experiment Democrats started in 2003 is now over. The Senate has taken a step back toward its centuries-old norms on nominations: limited debate and a simple majority threshold.

On legislation, however, the Senate’s treasured tradition is not efficiency but deliberation. One of the body’s central purposes is making new laws earn broader support than what is required for a bare majority in the House. The legislative filibuster does not appear in the Constitution’s text, but it is central to the order the Constitution sets forth. It echoes James Madison’s explanation in Federalist 62 that the Senate is designed not to rubber-stamp House bills but to act as an “additional impediment” and “complicated check” on “improper acts of legislation.” It embodies Thomas Jefferson’s principle that “great innovations should not be forced on slender majorities.”

The legislative filibuster is directly downstream from our founding tradition. If that tradition frustrates the whims of those on the far left, it is their half-baked proposals and not the centuries-old wisdom that need retooling.

Yes, the Senate’s design makes it difficult for one party to enact sweeping legislation on its own. Yes, the filibuster makes policy less likely to seesaw wildly with every election. These are features, not bugs. Our country doesn’t need a second House of Representatives with fewer members and longer terms. America needs the Senate to be the Senate.

I recognize it may seem odd that a Senate majority leader opposes a proposal to increase his own power. Certainly it is curious that liberals are choosing this moment, when Americans have elected Republican majorities three consecutive times and counting, to attack the minority’s powers.

But my Republican colleagues and I have not and will not vandalize this core tradition for short-term gain. We recognize what everyone should recognize — there are no permanent victories in politics. No Republican has any trouble imagining the laundry list of socialist policies that 51 Senate Democrats would happily inflict on Middle America in a filibuster-free Senate.

In this country, radical changes face a high bar by design. It is telling that today’s left-wing activists would rather lower that bar than produce ideas that can meet it.

I am known for appreciating an old Kentucky saying: “There’s no education in the second kick of a mule.” Some Senate Democrats seem to agree. Thirteen of their ranking members on Senate committees have publicly stated that they oppose tampering with the legislative filibuster.

But the Democratic Party is racing leftward, with presidential debates that make the 2008 exchanges between Barack Obama, Hillary Clinton and John Edwards look downright conservative by comparison. The party is rallying around the very kinds of radical schemes that the Constitution intentionally frustrates. And rather than moderate or engage in persuasion, many on the left seem more tempted to rewrite the rules once again.

A majority of the Democratic presidential candidates are flirting with ending the legislative filibuster. Even more irresponsibly, Chuck Schumer and Dick Durbin, the top two Senate Democrats, have signaled openness as well. On this subject, like so many others, what was recently fringe nonsense seems to be rapidly becoming mainstream Democratic dogma.

I hope the saner voices among Democrats can help their compatriots see reason. Unless and until that happens, Americans must never let this radical movement gain enough power to vandalize the Senate.

If future Democrats shortsightedly decide to reduce the Senate to majority rule, we’ll have lost a key safeguard of American government.

And — stop me if you’ve heard this one — they’d regret it a lot sooner than they think.

Mitch McConnell (@senatemajldr), a Republican from Kentucky, is the Senate majority leader.

The Times is committed to publishing a diversity of letters to the editor. We’d like to hear what you think about this or any of our articles. Here are some tips. And here’s our email: letters@nytimes.com.

Follow The New York Times Opinion section on Facebook, Twitter (@NYTopinion) and Instagram.