March 20, 2009 4:54 pm President Obama Learns a Lesson It appears that President Obama has weathered the storm over a comment he made on Thursday’s “Tonight Show.” But he learned that an offensive joke can’t be reversed once you’ve let the ball roll. Local 0:34 City College of New York goes remote as protests continue 14:23 NYPD arrests around 100 protesters at Columbia University 29:11 NYPD moves in on protesters at Columbia University making dozens of arrests 1:45 NYPD enters Columbia University in riot gear to clear protest 3:24 Mayor Adams and the NYPD urge protesters to leave Columbia University