Senate Democrats made a mistake when they eliminated the filibuster for lower court judges in 2013. They’re making the same mistake again - except this time with a far less certain payoff.

Vice President Kamala Harris said Tuesday that she favors lowering the existing 60-vote threshold to a bare majority to enact legislation to protect abortion rights nationwide. “I think we should eliminate the filibuster for Roe and get us to the point where 51 votes would be what we need to actually put back in law the protections for reproductive freedom,” she told Wisconsin Public Radio.

I would love to see a federal law that gives women nationwide the ability to decide for themselves whether to continue an unwanted or dangerous pregnancy. Harris’s solution is, unfortunately, the wrong way to do it.

Readers, if you disagree and are bristling with indignation at this statement, let me say: This is not an easy call. The filibuster is an infuriating, undemocratic impediment to progress - except, that is, when it is a welcome guardrail against extremism. How partisans feel about the filibuster on any given day tends to have a lot to do with whether their political party holds the Senate majority. Democrats and Republicans who lament the existence of the filibuster are thankful for it when they find themselves in the minority.

But it takes self-restraint, and an ability to see around corners, not to junk the filibuster when your party is in power - especially because partisans are convinced the other side will make that move if given the chance. Yet the ping-pong nature of Senate control means that neither Republicans nor Democrats can be confident that doing away with the filibuster won’t end up hurting them in the end, even if they profit in the short run.

Not just that: The notion that the rules can be tweaked for some limited purpose - Harris has previously said she would do so to pass voting rights and climate change legislation - is delusional. The filibuster slope isn’t merely slippery - it’s encrusted with ice. One exception will be followed by another.

We don’t need to predict this; we need only to look at recent history. In 2013, Senate Democrats, under the leadership of Harry M. Reid (Nev.), moved to end the filibuster for lower court judges. The reasons for employing this “nuclear option” were understandable; Republicans had engaged in unprecedented obstruction of President Barack Obama’s judicial nominees, refusing to allow him to fill any of three vacant seats on the critically important federal appeals court in the District of Columbia. And the move allowed the confirmation of three of the circuit’s finest judges.

It also had predictable consequences.

First, lowering the threshold for confirming judges dramatically changes the nature of these lifetime appointments. When their party also controls the Senate, it gives presidents the leeway - and therefore the incentive - to pick nominees near the extremes instead of the center. Think about President Donald Trump’s judicial nominations and how different they would have been - how much less extreme the federal courts would now be - if they had to pass a 60-vote hurdle.

Second, the notion that the line would hold at lower court judges was laughable at the time and quickly disproved. Democrats, justifiably angered by Republicans’ refusal to consider Obama’s nomination of Merrick Garland to the Supreme Court, filibustered Trump’s nominee to the vacant seat, Neil M. Gorsuch. Republicans then one-upped the 2013 Democratic maneuver and eliminated the filibuster for Supreme Court nominees as well, delivering to Trump the ability to confirm not only Gorsuch but also justices Brett M. Kavanaugh and Amy Coney Barrett.

So, here we are. The filibuster for legislation has been on life support for years now, in Republican and Democratic Senates alike, but there hasn’t been the will, at least not majority will, to pull the plug. Harris endorses this move for the best of reasons - protecting a woman’s right to choose - but we all know this would be the first carve-out, not the last.

It would clear the way for Senate Democrats to enact all sorts of progressive legislation - if they retain the majority, if they retake the House and if they win the presidency. Great, but imagine the frightening things that could happen when the tables are turned and Republicans regain power. Democrats might miss the filibuster once it’s gone.

And why announce support for an abortion rights carve-out now, with all those ifs looming? A motivating argument for senators of both parties considering whether to curtail the filibuster is that the other side will do it if given the chance. Now, in the not-unlikely event that Republicans regain control of the Senate, Harris has proved that point. Senate Republicans wanting to junk the filibuster could then credibly claim that Democrats were willing to do the deed themselves but could not seize the opportunity.

So, if you are cheering Harris’s remarks on the filibuster, think again. Is the risk worth it?