President Barack Obama left the heated partisan atmosphere in Washington on Wednesday for an overly warm hometown 50th Birthday Party with 2,400 fans and donors packing the historic Aragon Ballroom in Uptown. “It doesn’t matter how tough a week I have in Washington, because I know you’ve got me — you’ve got my back,” President Obama told the crowd. “When I come to Chicago, when I travel across the country, I know we can’t be stopped.” Introducing Obama, Mayor Rahm Emanuel said “This looks like the Uptown Music District,” a reference to one of the mayor’s pet entertainment projects. With...