WASHINGTON (CNN) – As President-elect Obama visits the White House, a new national poll suggests that the current occupant of 1600 Pennsylvania Avenue is the most unpopular president in the six decades since presidential approval ratings were first measured. Seventy-six percent of those questioned in a CNN/Opinion Research Corporation survey released Monday disapprove of how George W. Bush is handling his job as President. That's an all-time high in CNN polling, or in Gallup polling dating back to World War II. "No other president's disapproval rating has gone higher than 70 percent. Bush has managed to do that three times...