WASHINGTON --President Barack Obama is celebrating his 50th birthday at the White House Thursday. Obama's senior staff will toast the president in the Blue Room of the White House in the afternoon. And in the evening, the president will celebrate with family and friends, including some who came in from his hometown of Chicago. For the sake of his presidential campaign, Obama started his celebrations early. He headlined two birthday-themed fundraisers in Chicago Wednesday night. Supporters around the country also hosted their own 50th birthday events from coast to coast.