One more time: It was not about sex or infidelity, it was about perjury.
That said, Newt needs to forget about presidential ambitions.
Why?
Not so sure about that. Although his behavior was indefensibly wrong, he's taken responsibility for it. More than that: he's admitted that his was a moral/spiritual failure. Sounds like a penitent heart to me. Most Americans, even many of us who call ourselves conservative Christians, are quick to forgive under such circumstances.
I'm not sure yet whether I'd vote for him, but I know I want Newt running. For him to disclose this embarrassing info on Dobson's show suggests that he's getting serious about campaigning. Doing it before he jumps in shows some savvy, too.