In the midst of two wars and an intensifying economic meltdown, Barack Obama had to take time off last week to answer questions from federal prosecutors investigating charges that the governor of Illinois had put the president-elect's former Senate seat up for sale. With his own lawyer by his side, Obama sat down Thursday with U.S. Attorney Patrick Fitzgerald's staff to tell what, if anything, he knew about Gov. Rod Blagojevich's efforts to cash in on appointing Obama's Senate successor