There's still a group of Republican voters that have that position, but that position is a non starter for anyone running for President. Romney ran on a less hardline position of simply supporting "self deportation" and only won 29% of the Hispanic vote. Rand realizes that in order to win a general election he can't take a hardline stance on this issue and alienate Hispanic voters, so he's correctly taking a moderate to center-right position on this issue in order to give him a chance to win a general election. Even if his position hurts him in the primary, I think he just figures that there's no point of winning the primary if he can't win a general election. And yes, he is taking a position that some people view as "amnesty," although I wouldn't call it that.