For liberals, Ruth Bader Ginsburg’s death brings shock — that an icon is gone, that she didn’t make it until the next presidency — and terror: Senate Majority Leader Mitch McConnell, who in 2016 blocked President Barack Obama from filling a Supreme Court seat vacated about nine months before the presidential election, says he will permit President Trump to fill one left empty less than two months before this year’s election. McConnell announced hours after Ginsburg’s death that he would attempt to push a new justice onto the bench. “President Trump’s nominee will receive a vote on the floor of the United States Senate,” he said.

Democrats have only one play here: If Trump and McConnell jam an appointee through, it is not enough for Democrats to raise hell about the hypocrisy, the duplicity and the Republican refusal to play by McConnell’s own rules. It is not enough to target every Republican senator who goes along. It is not enough to have voters bombard their Republican senators’ offices with phone calls and protests. Because those things have been happening for four years, and none of them have persuaded the GOP to put the stability of the country or the obligations of office ahead of that party’s thirst for power.

So Democrats should threaten to pack the court. And, if McConnell pushes through a new justice and then Joe Biden wins, they should follow through.

Ginsburg herself was clear on what she believed to be fair. As she was dying, she dictated a public statement to her granddaughter: “My most fervent wish is that I will not be replaced until a new president is installed.” Before Ginsburg’s death, Sens. Susan Collins, Lisa Murkowski, Cory Gardner and Charles E. Grassley all stated, laudably, that they would not consider a Supreme Court nominee this close to the election. So far, only Murkowski and Collins have reaffirmed their position. Whether the other senators’ commitments will hold up when these senators face our new reality remains an open question.

The stakes are high. Trump’s Supreme Court appointees have already reshaped the American legal landscape. A conservative taking Ginsburg’s place could walk back women’s rights, LGBT rights, voting rights, union power and civil rights not just for a generation but potentially irreparably.

This is also a question of fundamental fairness and democratic norms. In order for a democracy to function, people have to play by the same rules. McConnell has made up the rules as he goes along, constraining Democrats and empowering his own party. He has shown, time and again, that preserving American democracy is not the goal; power is. We saw this when he thwarted Obama’s nomination of Merrick Garland. We saw it when he blocked any real impeachment trial and refused to call witnesses who might incriminate Trump.

Democrats need to realize that they’re up against a mendacious bully who is never going to follow even the rules he sets out. “Court-packing” is a loaded term, and if they’re smart, Democrats will find a more palatable one. But it’s a defensible and evenhanded move to assert that, if McConnell steals another Supreme Court seat (weeks before a national election), then Democrats will consider a presidential victory a mandate from voters to expand the number of seats on the Supreme Court.

This is not unprecedented. The number of justices has not been static at nine; it’s changed six times, from as few as five to as many as 10. All it takes is for Congress to pass an act, and for the president to sign it. If a Biden victory came with a Democratic congressional majority, expanding the number of Supreme Court justices wouldn’t be that hard to do.

Adding justices is not an action Democrats should take lightly. It runs a high risk of alienating some voters who would see such a move, constitutionally mandated though it may be, as taking advantage. And the escalation would certainly ratchet up the already boiling conflicts between Democrats and Republicans in Congress. But McConnell forces the left’s hand. Thanks to him and his ally in the White House, the United States looks less like a functional democracy by the day. This latest maneuver is more than political gamesmanship; it’s a massive blow to the stability of the republic.

With an election looming, Democrats can give voters a say. If they vow to expand the court, then Americans can cast their ballots with that in mind. Key to the message should be that McConnell and Senate Republicans have so repeatedly broken the rules, rigged the game and stolen victories that it’s become impossible to play on neutral turf. As Murkowski put it, fair is fair.

It’s a shame we’re here. But to restore a democracy that has been battered, bruised and robbed blind by the president and his party, Democrats will need to fight harder. If Republicans steal this seat, the only reasonable response is to change the number of judges on the bench.