So, no, maniac doesn't stick, it is a lie.
Trump could have gone after Cruz on electability, or on TPP or H1-B or something where they had a policy issue to discuss. But to attack him personally for being one of 4 or 5 conservatives in the Senate attempting to stand up to the Uniparty is wrong and Trump should be warned, by Rush and Levin and others, that he is going the wrong way.
Was Cruz wrong for saying Trump could not be trusted with his finger on the nuclear button? Should Trump ignore an attack like that? The quote from Ted Cruz proves he is a maniac.