With Monday’s swearing-in of new Supreme Court Justice Neil M. Gorsuch, the high court is back to nine justices after operating shorthanded for more than a year. While that is a welcomed development, the political fight that stalled the filling of this vacancy has diminished the standing of the Senate and likely assured the appointment of more strongly ideological nominees going forward.

Last week was a momentous one for the Senate, for the future of the Supreme Court, and for the way the American public can expect its justices to interpret the Constitution that protects their rights. When it became clear that Gorsuch could not get the 60 votes necessary to assure a filibuster-proof margin, the Democratic minority had two options. It could invoke a filibuster or it could allow a straight vote, knowing that would assure Gorsuch’s confirmation.

Democrats made the wrong choice.

Under the leadership of Minority Leader Chuck Schumer of New York, the Democrats invoked the filibuster. It was a decision based more on appeasing the party’s angry base than on the qualifications and judicial philosophy of Gorsuch. After years of watching Republicans in the Senate block President Obama’s appointments and agenda, many party faithful were in no mood to give President Trump and the Republicans an inch. Schumer complied with their wishes.

The Senate minority leader cloaked the decision in rhetoric about the sanctity of the filibuster. But it was the Democrats, when in the majority in 2013, who undermined the filibuster by scrapping it for lower court federal nominees and executive branch appointments. Yes, that move came out of frustration with Republicans making unprecedented use of the filibuster. But then-Senate President Harry Reid had to know Democrats were extending an invitation for Republicans to further erode the filibuster when they gained power and found it inconvenient.

As for the history of using filibusters to block controversial appointments to the Supreme Court, there isn’t any. In 1991, for example, Democrats, in firm control of the Senate, did not employ the filibuster to stop the highly controversial nomination of Clarence Thomas by President George H.W. Bush. Justice Thomas was affirmed 52-48. Republicans likewise did not attempt to filibuster President Obama’s first two appointments to the Supreme Court, Sonia Sotomayer and Elena Kagan.

However, the potential for a filibuster is something presidents have to had to factor into their calculations when making Supreme Court nominations. No longer. That is why Democrats should not have picked this fight and Republicans should not have so quickly abandoned the filibuster when they did.

Without a filibuster threat in place to temper presidential appointments, expect future nominations from the right and left that go further outside the judicial mainstream.

The most outrageous action, leading to this series of reactions, was the refusal by the Republican-controlled Senate to act on Obama’s appointment of Judge Merrick Garland to fill the vacancy created by the death of Justice Antonin Scalia in February 2016. In effect, the Republicans stole the seat Gorsuch filled, as Democrats charge.

Aged 49, Gorsuch will likely be on the court a long time. Yet his appointment does not change its ideological balance. The next vacancy may well do so. Justice Anthony Kennedy, often the swing vote in 5-4 decisions and author of the controversial ruling striking down as unconstitutional state bans against same-sex marriage, is 80. Justices Stephen Breyer and Ruth Bader Ginsburg, who consistently side with the liberal wing of the court, are 78 and 84, respectively.

If there are no further vacancies in the next two years, expect the 2018 Senate elections to include a debate over the future predilection of the Supreme Court unlike any in U.S. history.

Democrats will argue to a fired-up base that keeping the Senate in Republican hands could lead to a court stacked with conservatives and imperil protections for reproductive rights, voting rights, and separation of church and state. Republicans, likewise, will argue to their base that continued control of the Senate could mean locking up a court respectful of conservative values for at least a generation.

If Democrats recaptured the Senate in 2018, they could well refuse to fill any Supreme Court vacancies in the second half of Trump’s term, citing the precedent set by the Republican block of Garland, assuring the court’s makeup would be central to the 2020 presidential election debate as well.

A Supreme Court nomination process this politicized is unprecedented and it’s not in the nation’s best interests. Both sides deserve discredit for getting to this sorry point.