No matter what last-minute switches take place over the weekend, the Senate's vote margin on Supreme Court nominee Brett Kavanaugh's confirmation is likely to be the closest in modern American history.

And it may not be the last.

The cloture vote on Friday favored Kavanaugh by 51-49. That tally may not be repeated precisely in the actual vote for confirmation, but it is expected to be similar. If that is the case, the margin will still be closer than the 52-48 vote in October 1991 that confirmed Justice Clarence Thomas, also a target of allegations of sexual misconduct.

The anticipated narrowness of the Kavanaugh vote “reflects the modern polarization of the Congress, and so may be the future of all nominees,” said Tonja Jacobi, a Supreme Court scholar at Northwestern Pritzker School of Law. She said the margin could be very close “even when there are not such extreme policy views at play and even when there aren't multiple sexual assault allegations and claims of perjury.”

Until now, the Thomas margin appears to be the closest in recent years. Justice Samuel Alito Jr. was confirmed 58-42 in 2006—a 16-vote margin—and last year, Justice Neil Gorsuch was confirmed 54-45, a nine-vote difference.

Going further back in history, the Senate confirmed the nomination of Stanley Matthews by a 24-23 vote in 1881, a one-vote margin. He had been nominated earlier that year by President Rutherford Hayes, but was not acted on because of “his past support of Hayes … and the fact that he had served as attorney for powerful railroad and corporation interests,” according to Britannica.com. President James Garfield re-nominated Matthews who was then confirmed by the narrowest margin in court history.

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