Speculation about potential nominees has already begun, with Solicitor General Elena Kagan and Judge Merrick Garland of the U.S. Court of Appeals for the D.C. Circuit winning the most mentions at this early stage. Secretary of State Hillary Clinton is also the subject of growing speculation as a possible nominee.

That said, many Court-watchers still don’t believe two concurrent vacancies are likely.

“There’s a very express consensus within the Court that two vacancies not occur simultaneously, barring a medical tragedy,” said David Garrow, a high court scholar and senior research fellow at the University of Cambridge. “And there’s no new evidence that Justice Ginsburg is at all considering departing.”…

Another theory argues that, in a strange way, two vacancies at once might actually help Obama push through at least one liberal nominee. President Ronald Reagan perfected that strategy from the conservative side in 1986 when Chief Justice Warren Burger retired. Reagan nominated William Rehnquist, then an associate justice, to move up to chief and named Antonin Scalia to replace Rehnquist as associate justice. That meant hitting the Senate with two nominations at once. The Senate could only stomach one bruising battle that summer, it appeared, so Rehnquist took the heat while Scalia, who arguably should have troubled Democrats even more, sailed through without a dissenting vote.