I don't believe it's a case of Newt being "too conservative". It's more like Newt being "too unstable".
There is a thing called "Presidential Temperament". Whether Newt has it or not is a very open question.
I’m judging by the exit polls. They showed that voters voted for the candidate that was close to their ideology. As I recall, Newt won with conservatives, but Mitt won with the moderates. Not saying every state went down that way, just NH and FL.
There is also this thing called “PRESIDENTIAL MENTAL ACUMEN” ‘whether Sanctimonium has it or not is a very open question.’ He does, however, exhibit extreme “CANDIDATE DELUSION”, like when he tells a group of supporters, “God called me to run.”