Rush sounds fairly pro Cruz to me, he’s just not gone anti Trump.
I think Rush senses that Trump may win and since he is a friend of Trump, he just might get another invite the the White house.
Let me put this in perspective. Rush is fairly pro Cruz, but he's given the Trump campaign about 360 million dollars worth of free positive publicity since June. He mentions Cruz maybe a 50th of that much. He hasn't endorsed officially, but his entire program has been a Trump Show since June.
Second, four years ago he totally skewered Newt when Newt went LEFT of Mitt with the Bain Capital ads. And Newt deserved it. This cycle, Rush is floundering around avoiding doing the same to Trump. Rush has abandoned what he stood for over 28 years for his own fan boy infatuation.