How much should voters know about their candidates? And does that include matters of their personal life?

http://firstread.msnbc.msn.com/archive/2008/03/25/807581.aspx

It was predictable that this would come up one of these days in this campaign. And that's what's so sad about it.
I believe what this country might need is a serious debate about how far the media should go in exposing a candidate's/president's personal life.
The scandal of 1998 was one of the occasions where they definitely crossed the line. That doesn't mean that the president's doings or his lying about them were appropriate. However, he should NEVER have been asked about it in the first place. That sort of thing is no one else's business.
What's even worse is that this is still being brought up, 10 years after the fact, when there are so much more important things to discuss.
What I'm saying is, people need to stop looking for the perfect president, because such a person simply doesn't exist. A president is as human as the rest of us, and yes that means he does make mistakes. The question is, which of these mistakes should be put on national television, and which ones ought to be kept private.
I invite your thoughts.