If Rush wanted to endorse Fred he would. He has not done so. It would be bad for business and Rush is a consumate professional.
___________
I read your statement that Rush is a consummate professional to mean that he is not interested in damaging his credibility (earning power) on air by endorsing a candidate who has yet to show that he can attract significant support. Not a knock on Fred, just an observation.
I don’t think Rush would endorse Fred whatever level of support Fred was drawing. Rush makes his living by attracting listeners. Endorsing a candidate, any candidate, will drive away those listeners who support someone else. Rush gets paid big money because those who pay him expect him to keep his eye on the bottom line. That’s how business works.
Yep. The only reason.