The first appearance by a sitting president on "The Tonight Show" may well end up being the last. President Obama, in his taping with Jay Leno Thursday afternoon, attempted to yuk it up with the funnyman, and ended up insulting the disabled. Towards the end of his approximately 40-minute appearance, the president talked about how he's gotten better at bowling and has been practicing in the White House bowling alley. He bowled a 129, the president said. "That's very good, Mr. President," Leno said sarcastically. It's "like the Special Olympics or something," the president said. When asked about the remark,...