I think Cruz has less of a chance than Huckabee or Santorum did in 2008 and 2012 respectively.
Huckabee and Santorum were different animals. Santorum was a default Romney alternative who only became a runner-up after all the other campaigns collapsed. Huckabee on the other hand, actually excited social conservatives. In that way, Cruz is more like Huckabee, but even stronger since he excites a wider range of conservatives. Still, it might be true that he has less of a chance than Huckabee in 2008 (mostly because he'll have Carson and others, maybe Huckabee in the race). But Huckabee actually had a decent chance to be the nominee in 2008. He almost won both Iowa and South Carolina. So Cruz can have less of a chance than Huckabee but still a pretty good chance to be the nominee.
Another significant difference is that Cruz, unlike Huckabee and Santorum, can raise real money to compete.
