Are you stupid or are you a liar?
I am neither. Cruz was vice-chair of the Committee that ran racist ads against McDaniel. He never stood up during the primary WHILE the ads were running and said he couldn't be part of a committee that was doing that. Or call out the NRSC, that might have made a few headlines and stopped the ads right then and there. Or gone down to Mississippi.
He stayed out of sight until it was all over, knowing what he knew, and then talked to Mark Levin after the fact doing his usual principled conservative, these charges should be investigated.
In other words, he had it both ways which is the Cruz hallmark. He was loyal to the perpetrators and kept his mouth shut. He could have fought the committee on the inside or gone rogue. And then when the dust cleared, there was Ted calling for an investigation. Not unlike, when he told his donors behind closed doors that gay marriage was not a priority.