President-elect Donald Trump is deeply, deeply “indebted” to the Senate Democrats.

Long before there was any dream or whispering of a Trump Presidency, the Senate Democrats eliminated the filibuster for nominees to all Executive Branch positions and Judicial Branch positions beneath the Supreme Court. That was in November 2013.

Almost exactly three years later, one of the Democrats’ worst nightmares became true.

In the Senate, a filibuster is an attempt to delay or completely defeat business the Chamber is considering. The most famous filibuster, at least in the public mind, actually comes from Hollywood, in Mr. Smith Goes to Washington, where Jimmy Stewart talks himself hoarse until he collapses. That’s a spectacular way to do it, but most filibusters are not only less melodramatic, but are usually silent, consisting of whatever parliamentary maneuvers can halt the progress of Senate business until the majority can round up 60 votes.

By tradition and by rule, the Senate—the World’s Greatest Deliberative Body—enjoys unlimited debate. This is done because the Senate is supposed to be the place where political minorities have their say, where they are protected from a majority juggernaut. According to a hallowed image attributed to George Washington, the Senate is the “saucer” wherein the “hot coffee” of the House is poured to cool off.

Although the Senate likes to take its time, the Chamber can end a filibuster by voting to end debate, a practice called “invoking cloture”. Until November 2013, most business required a yes vote from 3/5 “of the Senators duly chosen and sworn”—i.e., out of all Senators currently in office—to cut off debate. When there are 100 Senators in office (as there usually is), you need 60 Senators to cut off debate. (The exception—again, until November 2013—was debate on changes to the Senate rules. Those debates could only be ended by an affirmative vote of 2/3 of “the Senators present and voting.”)

The 60-vote threshold for ending debate on nominees for all Executive Branch positions and Judicial Branch positions beneath the Supreme Court was the norm, as it still is for legislation. However, when the Democrats controlled the Senate in 2013, their Majority Leader, Harry Reid, had become frustrated by his continued inability to confirm three 3 nominees to the powerful D.C. Circuit Court of Appeals. So, to speed things up, Reid decided to reduce the number required to invoke cloture to a simple majority—51 Senators.

The way the Senate eliminated the filibuster was particularly problematic. They used the so-called “nuclear option” to make the change—something that both parties had threatened, but didn’t follow through with until November 2013. As mentioned above, to change the Senate rules, the majority needs 67 votes to invoke cloture. The Democrats did not have that, so then-Majority Leader Reid deployed an elaborate scheme to change the Chamber’s precedents. Both the House and Senate have precedents that determine how their rules are to be implemented. When the Presiding Officer applies the precedents during debate, if a Senator disagrees, he may appeal to the whole Senate to sustain or overrule the decision, and it takes only a simple majority to overturn the decision, thus setting a new precedent. So when bringing up one of the D.C. Court of Appeals appointees for a vote, Reid made a point of order that the Senate only needed a simple majority to invoke cloture for such a nominee. The Presiding Officer dutifully overruled him. In the scripted procedure, Reid appealed the ruling of the Presiding Officer, saying only 51 votes should be required for presidential nominees (other than Supreme Court nominees, for no particular reason). The motion Reid made was non-debatable and only required a simple majority to succeed. All the Republicans voted against this new precedent; only three Democrats—Senators Joe Manchin of West Virginia, Mark Pryor of Arkansas, and Carl Levin of Michigan—joined them. Except for these three Democrats, it was an utterly partisan affair. (For the transcript of the parliamentary maneuvers involved in this complicated procedure, see the Congressional Record for November 21, 2013. For other commentary on the use of the nuclear option, see our prior post on the topic. Levin would strongly criticize this breach of Senate tradition and rules both on the day of the nuclear option and in his farewell speech—both worthwhile reads.)

Now, it’s true that if the Democrats had lowered the threshold for appointment confirmation the more difficult way—mustering 67 votes to invoke cloture, rather than simply changing the precedent—President Trump would have still benefited. But Majority Leader Reid’s chosen method had other repercussions. For instance, it eroded already frayed bipartisan relations. “Temper Flare as New Senate Rules Strain Senate”, declared one New York Times headline.

But there was a further, deeper implication: Since the Senate could change that precedent, is there any way to stop the Senate from changing any other precedent by the same means? Could the Senate eliminate the filibuster entirely appealing previous precedents, just like Senator Reid did? The day Senator Reid changed the rules through his parliamentary sleight of hand, the Senate became much more like a majoritarian body, where the party in control can do as it pleases. In November 2013, when the Senate triggered the nuclear option, we predicted that if allowed to stand—and it’s difficult to see how the toothpaste can be put back in the tube—the Chamber, in fact, has no rules other than what 51 Senators are able to pass. Alternatively, the only traditions the Senate has are those subsequent Majority Leaders may be willing to protect.

And there will likely be a lot of pressure by supporters of President Trump to expand this further. Consider this: When then-Majority Leader Harry Reid triggered the nuclear option, he was careful to leave in place the filibuster for nominations to the Supreme Court. President Trump already has one Supreme Court nomination to make to fill the vacancy left by the death of Justice Antonin Scalia. It is possible President Trump could have two to five more if he should remain President for eight years. Besides the current opening, two justices are over 80 years old; another is almost 80, and a fourth is almost 70. As of today, the Democrats can still filibuster Supreme Court nominees, but if they do, there will be loud cries from the right for the Senate to use the same means Harry Reid did of eliminating the filibuster on all other Judicial Branch nominees. They will come from two important (and sometimes overlapping) constituencies: the dedicated and well-organized pro-life movement, which would see this as its best shot at overturning Roe v. Wade, and Republican proponents of Justice Scalia’s philosophy of interpreting the Constitution literally to make Court decisions. There will also be more than a little schadenfreude as Republicans exacted revenge upon the Democrats for their use of the nuclear option.

Aside from Senate Republicans, there is another who would like to see presidential nominees confirmed: President Donald J. Trump himself. Will he be tempted to lean on Senate Majority Leader Mitch McConnell to do away with the filibuster for Supreme Court nominees? Why not legislation? What would McConnell do then? McConnell reportedly has a good political poker face, so we won’t take a guess as to what he would do in the face of immense pressure like that. Nor will we take a gamble on how the filibuster for legislation fares. But it should be duly noted that Senator McConnell is a traditionalist who believes the Senate’s distinct role in the legislative process. That being said, Majority Leader McConnell is hardy likely to use the same process as his predecessor to undo the change in precedents for fear that by doing so, he legitimizes a procedure he believes to be illegitimate. Any change to cloture will have to be done by an amendment to the Senate rules, and that will require a 2/3 vote, and substantial Senate Democrat participation.

In November 2013, now-retired Senator Harry Reid won the elimination of the filibuster for most appointments. But that was just the short-term. In the long-term, his legacy will be that of Senate Democrats, now in the minority, impaling themselves with the tool they fashioned to spear the Republicans—or as Shakespeare put it, they’ve been “hoisted on their own petard”.