Barack Obama is not used to being the guy not invited to a party. At the Copenhagen global warming conference, however, he found that not everyone wanted to hang with him. Our president can't take a hint. ..."We weren't crashing a meeting," an Obama flack later explained defensively. "We were going for our bilateral meeting." But that didn't stop him from walking in where he wasn't invited. Clearly, Mr. Obama learned a few things from his own White House party crashers.