Let's think about this logically for a moment: You want me to not vote for Trump because in the past he holds a position that your candidate holds today?
Why would I be voting for your candidate?
Why vote for Cruz over Trump? To put it concisely, because he has a long, consistent record of strong conservative leadership.
And my point was that if you are viewing immigration as the end-all, be-all issue, the sad fact is that NO candidate has a consistently strong enough position on that issue. Not even Trump.