Republican calls for Barack Obama to refrain from nominating a successor to deceased supreme court justice Antonin Scalia are “odd” and “absurd”, according to constitutional scholars and experts.

“The arguments that they are making – that this is a matter of principle – are nonsense,” said Michael Dorf, professor of constitutional law at Cornell Law School. “It’s just that they politically want some different kind of nominee.”

Within two hours of official word about Scalia’s death, the Republican leadership was quick to draw its line in the sand, led by the Senate majority leader, Mitch McConnell. “The American people should have a voice in the selection of their next supreme court justice,” McConnell said in a statement. “Therefore, this vacancy should not be filled until we have a new president.”

The American people do have a voice, said Dorf. “It’s through President Obama and the current Senate. If they lack legitimacy to do this, how do they have legitimacy to do all sorts of other things that have long-term consequences?”

Dorf called the GOP demand “absurd”, and said that while such appointments were uncommon, “the fact that it’s rare doesn’t mean that it’s an argument to not do it.”

If approved by the Senate, a justice chosen by Obama could fundamentally alter the character of the nine-member court, which until Scalia’s death often split down ideological lines on polarizing rulings. Scalia, who died on Saturday night, was the court’s most reliably conservative justice. Justice Anthony Kennedy was often seen as the swing vote between what was otherwise roughly speaking a court of four liberals and four conservatives.

Shortly after Scalia’s death, the Senate judiciary committee chairman, Chuck Grassley, erroneously said in a statement that “it’s been standard practice over the last 80 years to not confirm supreme court nominees during a presidential election year”. Presidential candidates Marco Rubio and Ted Cruz also repeated this line during the GOP debate on Saturday night.

In fact, election-year confirmations have occurred five times in the past century. The most recent, Kennedy, was nominated by Ronald Reagan in November 1987, and confirmed in February 1988 – 280 days before that year’s presidential election, although in Kennedy’s case the vacancy occurred earlier.

In both cases “you’re still many months away from the election, and [in this case] almost a year away from the end of Obama’s term,” Dorf said.

Still, election year confirmations are less common than confirmations during other times. “We don’t get these vacancies very often because people time their retirements. It’s harder to time your death unfortunately,” said Barry Friedman, constitutional law professor at New York University and author of The Will of the People, a book exploring the relationship between the supreme court and public opinion.

Friedman said it was not surprising that Republicans would delay on any likely Obama nominee given the close proximity of the election, but called it “odd” that so many lawmakers had publicly declared they would not vote for any Obama nominee on principle. “What caught me off guard is how quickly the arguments seemed to be made that there was some constitutional norm here – there’s not,” Friedman said.

Besides Kennedy, the nearest historical example similar to the one Scalia’s vacancy has created is that of former justice Abe Fortas. In fact, two separate confirmation battles at the end of Fortas’s four-year supreme court career loom large over the current nomination battle.

In 1968, Fortas, who had been successfully nominated by Lyndon Johnson, was selected to replace the retiring Earl Warren as chief justice of the court. As it was an election year, a broad swath of conservative southern Democrats (called Dixiecrats) and Republicans joined forces to successfully block the elevation of Fortas, who supported civil rights for black Americans.

Strom Thurmond, the unabashedly segregationist senator from South Carolina, led the efforts to stymie Fortas, invoking what has since been become known informally as the “Thurmond Rule”. This is the non-binding Senate tradition of resisting supreme court appointments in the final months of a presidency that McConnell and other Republicans have essentially been alluding to since Saturday. The pressure was so great that Johnson withdrew the nomination a few months later and Warren decided to remain as chief justice.

Then, shortly after the 1968 election, an ethics scandal forced Fortas’s resignation from the court. Under newly elected Richard Nixon, it took a record 391 days to fill his vacancy, as Nixon’s first two nominations were rejected by Congress. The open seat was eventually filled by Justice Harry Blackmun.

In its time, the Fortas vacancy was simply without precedent. According to the congressional research office, from 1900 to 1980 the average time from nomination to confirmation for an incoming justice was 59 days. Although this duration nearly doubled in the period from 1980 to 2010, ballooning to 113 days, a holdout over Scalia’s seat for the remainder of Obama’s term, 341 days from his death, would more than triple the current average and drift quite near to the Blackmun-Fortas record.

But this record vacancy was not a product of the Thurmond Rule or any sort of constitutional standard that negated a president’s ability to nominate as a “lame duck”. Rather, it was a matter of the normal partisan political maneuvering that has defined supreme court confirmations for at least the last century. Scholars like Friedman and Dorf both say that ultimately, once the political grandstanding quietens down it is this less extraordinary process that will dictate the timing of Scalia’s replacement.

“It’s the president’s job to realize there’s a vacancy on the court and he should pick a nominee, and the Senate should get that name and do what politics does with it,” Friedman said.