'O'Bama' nod to Irish heritage on St. Patrick's Day

Sporting a green tie and waving a poetry anthology, US President Barack Obama marked St. Patrick's Day at the White House Tuesday, an opportunity, he joked, to "trot out" his Celtic roots. "This is an annual affair and always one of my favorites," Obama said, welcoming Taoiseach (Irish Prime Minister) Enda Kenny to the Oval Office. Since coming to office Obama has embraced a tradition, began by president Harry S. Truman, of marking this festival of all things Erin.