My impression is that Rush is definitely pro-Trump and way more excited about Trump's candidacy than he was by the McCain and Romney candidacies. Moreover, he's clearly intrigued by Trump's unconventional campaign tactics.
Occasionally, though, Rush finds something to criticize or question -- the articulation of a particular policy or an ill-advised attack or response, etc.
By your definition, however, if one doesn't wave pom-poms and uncritically lead cheers after every Trump utterance, one is somehow anti-Trump. Seemingly, you cannot bear to see or hear your political god being questioned. Many Trump supporters seem to feel this way.
Such an uncritical, unquestioning attitude toward political leaders is what got us into this fix in the first place.
We each have our own perception.