Because even if they were not the source of the incorrect information, they did pass on incorrect information. Apologizing is the classy and proper response. I'm sure that is a hard concept for Trump supporters to comprehend - nobody would use the word classy in association with Trump.
Here’s the tweet;
https://twitter.com/CNN/status/694326400006762496
Go to post 16 and see what the Cruz team said. What they said wasn’t what the tweet said. There is no way to logically or coherently make the case what the Cruz team said is what the tweet said.
Own it.
Steve King R-Iowa commented on this. He was involved and had noted to his staff that something was up with the Carson campaign. His staff passed the info to others, and others made assumptions, and yes, some voters got erroneous info. There is no indication Cruz had anything to do with this.
As King noted, this broke just as the vote was about to be taken. He noted that it would have been even worse if Carson had actually quit at that moment and the news was not provided to the Carson voters in the room.
That dog named Fraud just don’t hunt on this matter.