I disagree.... This is his chance to own it. I think he should make the most of it. And I don’t agree with your premise. I think he can syphon conservatives away from most of the others.
If anybody out there is still for Huckabee or Santorum or Paul it may be because they've already decided they don't like Ted. Ditto for Carson voters.
One of the things we've seen in previous elections is that conservative voters don't necessarily go to the most conservative or next most conservative candidate if they're own choice drops out.
I'm not saying Ted won't get any of them, but there's no great bonanza of voters that will flock to Cruz because he disses New York. Cruz has already taken votes from Carson, but even if he gets most of the rest (which he may not) it still won't put him ahead of Trump.