Happy Birthday, Joe

Seventy-eight candles on a birthday cake is an achievement in longevity for anyone, and Joe Biden earns the flames-and-frosting trophy this Friday. As Mr. Biden and his partygoers prepare to take over the White House, here’s a wish for four years of good health.

America’s oldest President to date, Ronald Reagan, was three weeks shy of 78 when he left the Oval Office for the last time. The second oldest President, Donald Trump, will be 74 1/2 on Jan. 20. From there, the record drops to roughly age 70 for Dwight Eisenhower…