An Interruption | 3:08 p.m. A lone protester shouted, and then a chant erupted to follow soon after Mr. Obama began speaking. As police officers took the protester away, much of the stadium cheered his removal. A few moments later, another single protester began shouting “Abortion is murder.” The crowd erupted with loud boos directed at the heckler and then broke into loud chanting of Mr. Obama’s campaign slogan, “Yes, we can.” “We’re fine, everybody,” President Obama said, calming the students, some of whom had stood up. He continued to ad-lib based on the theme of his speech, saying: “We’re...