As President Biden gears up for a star turn on the world stage at the G7 summit, concerns are rising at home in respect of the age — and, potentially, fitness for office — of the chief executive. More than 60 House Republicans are even asking Mr. Biden to be evaluated as to his “current cognitive state and ability to serve another term as President.” It’s a problem anticipated by the Framers, who anticipated the need for “energy in the executive.”