You have about 5 weeks to put forward someone else. And no, unlike Cain and Perry, Newt isn’t some fresh face that can be taken easily down due to people not knowing who he is. So negative ads aren’t going to cut it.
With Newt pushing double digit leads all over the place, I don’t see someone bumping him off.
The general electorate knows almost nothing about Newt. What they will know is what the MSM tells them.