I clipped my toenails today. Word has it Andy would approve...
But back on topic, if every presidential candidate had to be screened for their associates in life, George W would have a string of coke-addled alcoholics. Reagan was pals with people who killed priests, supported Saddam Hussein and Osama Bin Laden (against the Soviets), and on the racism card, the guy even kicked off his presidential campaign in the town famous for "Mississippi Burning". Abraham Lincoln was one of the worst offenders of the concept of "patronage" -- often choosing sometimes crooked "friends" for the political purpose.
Not to defend who Obama befriends here. But be realistic. To be a politician in this country and to get where you are, you're going to make some compromising friends and relationships along the way. To say any of those presidents above shouldn't have gotten in on that basis of their friendships and alliances would be more than a bit myopic.