The Constitution is very clear about what must happen now, in the wake of Supreme Court Justice Antonin Scalia's passing: "The President shall nominate, and by and with the Advice and Consent of the Senate, shall appoint" a replacement.

But less than an hour after Justice Scalia's death became public, Senate Majority Leader Mitch McConnell declared that the Republican majority would refuse to do its constitutional duty. In fact, Senate Republicans announced that they would outright refuse to consider, or even meet with, anyone President Obama should nominate.

There is no doubt that they would prefer that this vacancy have occurred with a Republican in the White House. But there is no excuse for their outright refusal to fulfill the oath they each swore to uphold and defend the Constitution.

And, despite Senate Republicans' misleading claims, there is absolutely no precedent for this stunning display of partisanship.

As senators of opposing parties whose Senate experiences cover the last five decades, we may disagree on matters of Supreme Court jurisprudence. But we agree that we should measure Supreme Court nominees by their character, intellect, judgment and experience — not by their ideological or partisan allegiances. And when it comes to the facts on the process by which those nominees have been considered and confirmed throughout our history, there can be no honest disagreement at all.

Since the Senate Judiciary Committee began to hold hearings in 1916, there have been 55 Supreme Court nominations. Every single one of those nominees has received a hearing, with just 10 exceptions: one nominee who withdrew before her scheduled hearing could be held, and nine who were confirmed within 11 days of being nominated.

In other words: Not once in the last century has the Senate simply refused to take action on a Supreme Court nominee, much less announce in advance that it will refuse to take action on any nomination a particular president makes.

Still, Senate Republicans demand that this Supreme Court seat remain vacant until after a new president is elected and inaugurated — because, in McConnell's words, "[t]he American people should have a voice in the selection of their next Supreme Court justice."

This is both dangerous and misleading. For one thing, inviting candidates and voters to treat this election as a referendum on the identity of the next justice will only further politicize the court — and encourage partisans on both sides to make up their minds before carefully considering any potential nominee's qualifications or judicial temperament.

Moreover, the American people have already spoken, twice, electing and re-electing Obama. The Constitution does not declare that, at a certain point during the four-year presidential term, the president loses the power to fulfill some of his duties. Nor, for that matter, does it absolve the 34 Senators in the final year of their terms from their responsibility to fulfill their duties.

Some Republicans are engaging in misleading rhetoric to excuse their obstruction. "It's been standard practice over the last 80 years," said Sen. Charles Grassley, Republican chairman of the Judiciary Committee, "to not confirm Supreme Court nominees during a presidential election year."

Grassley is wrong. Associate Justice Anthony Kennedy, who serves on the Supreme Court today, was considered and confirmed by a Democratic Senate in 1988 — a presidential election year, and President Reagan's last year in office.

In arguing for Kennedy's confirmation, Reagan declared, "Every day that passes with a Supreme Court below full strength impairs the people's business in that crucially important body."

But Senate Republicans say they will refuse to even consider a nominee until a new president takes office next January, which would leave the court short a justice well into next year. This would cripple the court not just for the remainder of the current term, but also for most of the next term, which runs through June 2017. And because the court decides which cases to hear in the months before a term begins, a vacancy that goes unfilled through the middle of 2017 could even affect the court's ability to function in the 2017-18 term.

This partisan gamesmanship threatens to harm more than the court's day-to-day operations. The Supreme Court, as the final arbiter of enormously consequential issues that affect every American, must remain above politics in order to retain its credibility. But now Senate Republicans would reduce the highest court in the land to just another political spoil, an election-year talking point. That is no way to determine the makeup of the highest court in the land.

We urge Senate Republicans to reconsider — and to do their job.

Al Franken, a Democrat, represents Minnesota in the U.S. Senate. Dave Durenberger, a Republican, represented Minnesota in the U.S. Senate from 1978 to 1995.