Because it would make sense for Santo to endorse Cruz, as Santo has always presented himself as this solid conservative and pro-life warrior. Trump, not so much.
I think Santorum can endorse whoever he wants. and he knows these candidates a lot better than any of us do. I also think that most of them can’t stand sleazy, slimy, creepy Cruz. No president is going to overturn Roe vs. Wade anyway - not Trump, not Cruz, not any of them. Are you a one issue voter? I assume so. However, Trump is also pro-life - he might not have been a few years ago, but people do get their eyes opened if they are teachable. Unlike you Cruzbots who have a know-it-all attitude - just like your candidate. He isn’t even dry behind the ears yet - let alone lead this country - he has no vision to lead us out of this mess we’re in.