Should the U.S. have some sort of more formal leadership training or licensing or academic requirement for anyone who runs for a federal office? Take a look at the list of five First Tier candidates for the 2016 presidential election, as determined by the University of Virginia's Center for Politics: former Gov. Jeb Bush of Florida, Gov. Scott Walker of Wisconsin, Sen. Rand Paul of Kentucky, Gov. Chris Christie of New Jersey and former Secretary of State Hillary Clinton.