U.S. Senate Majority Leader Bill Frist said today he hasn't ruled out a run for the presidency in 2008 but stressed that he hasn't given the matter much thought. Frist, who was the keynote speaker at a Leadership Knoxville Alumni Luncheon, said he is concentrating on his role in the Senate and will put off any decisions on future political moves until after he steps down in 2006. "I'm going to come right back home to Tennessee," the Nashville Republican said. Frist said he might ponder a presidential bid "if that were an option" after he leaves the Senate but...