That wasn't a big deal. Carson was finished and everyone paying attention knew it. The "voter violation" mailer was the big unforced error there.
But even that wouldn't have amounted to much if Cruz had what it takes to win. Trump makes bigger mistakes than Cruz at least once a week but he slides right past them. Voters will forgive a lot if you've got the right stuff.
If you don't, forget about it. I asked before for one example of Cruz having a great moment in the debates, something on par with Christie's takedown of the Rubot. Nothing. Cruz doesn't have it.
I didn’t watch all the debates but I like when he called Rubio out in Spanish. Watched Rubio a bit on Hannity. Funny thing, Hannity is 6 foot and Rubio is 5 foot 8. They had them staged to be the same height and a flag was carefully ran behind them so that Rubio looked higher on the striping. No photoshop necessary