WASHINGTON, DC – AUGUST 28: US President Barack Obama (R), first lady Michelle Obama (L) and Lynda Bird Johnson Robb attend the “Let Freedom Ring” commemoration event August 28, 2013 in Washington, DC. The event was to commemorate the 50th anniversary of Dr. Martin Luther King Jr.’s “I Have a Dream” speech and the March on Washington for Jobs and Freedom. (Photo by Michael Reynolds-Pool/Getty Images)