A Switch in Time Saved Nine

"Shesol also draws attention to a more mundane but nevertheless considerable factor in the shift of the court. In 1937 Roosevelt supported, and Congress approved, a bill to assure retired justices that they would continue to receive their judicial salaries even after retirement. The absence of such benefits had deterred some aged justices from retiring; once the pensions were assured, several of them resigned."

Alan Brinkley in The New York Times reviews Jeff Shesol's Supreme Power: Franklin Roosevelt vs. the Supreme Court.