The Presidency is not merely a political figurehead. The person holding the office is supposed to be a leader. And, if you cannot trust the fundamental character of a leader you need a new leader.As a child, it used to be common for kids to say "I want to be President when I grow up". The President was someone we were supposed to admire for all the right reasons and chief among them was the persons character. A list of Leadership Traits and Principles used to train Marines quantify the importance of character in a leader.
To put a point on it, the name of the game is character. The word itself has positive and negative aspects. If you say, "That George, he's such a character" the impression is often good. But, tell someone that they are not real, they are "just playing a character"; and depending on context it could be a bad thing. Then there is character in the form of the gestalt of personality traits and quirks that often defines if one is perceived as a good and moral person.
Mitt Romney, as a person, appears to be a man of character. I've seen nothing to indicate that he is anything but a loving father and husband. He is devout in his faith. As a person of high morals I'd say that he is a man of good character. Politically I cannot endorse him since he reminds me of the typical chamelion politician. But that is a professional observation.
Newt, on the other hand, is the opposite of Romney. Newt is a great politician. But, his character stinks. He is a serial adulterer, his ethics are atrocious, and a he's moral hypocrite to boot. I used to be a fan back in the day until his (now) obvious character flaws came to light.
Ron Paul appears to have the character of Romney in his personal life. Politically, his character is one of consistency over about thirty years. So, I can vote for him instead of simply against President Obama.