As former US president Barack Obama’s second term drew toward its close last July, he exercised his veto power for the eleventh of 12 times, shutting down “The Presidential Allowance Modernization Act of 2016.” The bill, which easily passed both houses of Congress, would have reduced former presidents’ pensions and staff allowances dollar for dollar if their other incomes exceeded $400,000 per year. In the wake of Obama’s decision to accept a $400,000 fee for a Wall Street speaking engagement this September, the bill’s sponsors plan to reintroduce it. But neither the speaking fee nor the...