At Philadelphia’s 30th Street Station on Tuesday, lifelong government rail promoter Vice President Joe Biden unveiled a $53 billion high-speed train initiative and half-joked: “I’m like the ombudsman for Amtrak.” As with most gaffetastic Biden-isms, the remark should prompt more heartburn than hilarity. Just who exactly is looking out for taxpayers when it comes to federal rail spending?

Vigorous independent oversight of public infrastructure binges is especially critical given the nation’s long history of mass transit slush funds, cost overruns and union-monopolized construction projects to nowhere.