Obama's Ethical Standards under Attack, but What about Hillary?

One prominent feature of American political campaigns is what is politely called "opposition research." That means digging up whatever you can about an opponent's record to make him or her look bad, hopefully by finding embarrassing contrasts to the candidate's current positions. Lately, the Obama and Clinton campaigns have been exchanging accusations about each other's positions and past records. Tom Hamburger, who covers money and politics for the Los Angeles Times, has some details.