Been doing that for a long, long time during this election cycle. First, he thought Rubio was the man. Then he hitched his wagon to Cruz. At that point, he started insulting Trump, and his supporters, at every turn. He's just keeping up the status quo!
Commenting to your comment. I seldom turn on Rush anymore. He's disgusted me to the point I cancelled my 24/7.(which I've mentioned on countless posts)
His position on candidates this election cycle has completely outed him for what he is. I started listening to him when he was local in Sacramento (I lived in the foothills). He changed a lot during the years. I was a faithful listener for quite some time.