Katie Couric's Primary Question on tonight's CBS Evening News is sure to stir up some interesting answers from the presidential candidates. Couric asks, "Harry Truman said, 'A man not honorable in his marital relations is not usually honorable in any other.' Some voters don't feel comfortable supporting a candidate who's not remained faithful to his or her spouse. Can you understand their position?"

Clearly, Sen. Hillary Clinton's answer will be of interest. According to the CBS press release, part of the answer she gives is, "I think there's more to someone's honor and integrity, and to their public service. I think sometimes we confuse the private and the public in ways that are not necessarily-- useful."

Also, with reports of a Sen. John Edwards extra-marital affair and subsequent pregnancy, his answer will be looked at more carefully as well. He said, "I think the most important qualities in a president in today's world are trustworthiness-- sincerity, honesty, strength of leadership. And-- and certainly that goes to a part of that. It's not the whole thing. But it goes to a part of it."

Couric's Primary Questions series began Tuesday, Dec. 4, with Couric asking the top 5 candidates from each party the same question. Some previous questions have been "When was the last time you lost your temper-and what came of it?" and "What is the biggest mistake you ever made?" The series has had mixed reactions, with some noting how earnest the questioning was, while others cite that some questions have been softballs.