Running for president of the U.S. requires something of an iron gut. It’s important to be seen enthusiastically consuming the local delicacies but it’s also critical to avoid a culinary faux pas: don’t ask for Swiss on your Philly cheesesteak or ketchup on your Chicago dog. Hillary Clinton joined Stephen Colbert for lunch yesterday at New York’s Carnegie Deli, where she was given a lesson on the proper way to eat New York cheesecake. Watch and learn.