Obama Clinching Nomination

April 22, 2012 - 9:17 AM
FILE - In this April 18, 2012, file photo President Barack Obama waves to a crowd as he arrives at an airport in Detroit. Obama will clinch the Democratic nomination for president Tuesday, April 24, ending a low-key primary race that many Americans probably didn't realize was happening. He's certain to reach the 2,778 delegates needed to secure his party's nod when five states vote on Tuesday. (AP Photo/Carolyn Kaster, File)