Now read the article.
"Then, Cruz may have an ace in the hole since he has moved in skillfully behind the primaries that have already been held to get as many second ballot delegates as possible. In many states — like South Carolina — delegates are not selected in the primaries, but rather at subsequent caucuses. If Cruz can fill the seats with delegates favorable to him, they can switch on the second ballot having satisfied their legal obligations by backing Trump on the first ballot."
Like I said, it comes down to a hope that the powers that be will allow him, a man who until a few months ago was the most hated man in the GOP, as the nominee at the convention: Dream on.