I am self identified (accurately I believe) as a “conservative. I believe it to be a good, correct and fairly descriptive of my political attitudes toward government, constitutional interpretation and moral/ethical values.
The problem is not the designation but, rather, it’s overuse and misapplication to people or situations inaccurately.
The media is famous for labeling someone as “conservative” when their historical beliefs/behavior are anything but.
Conservative describes MY political attitudes better than “right” and certainly more accurately then “Republican”.
Bingo.
The problem as discussed by Rush and the caller was simple; "conservative" no longer tests well. If you can no longer market it, and rehabilitation of the term is a long shot at best, simply rebrand around Trump and his platform. That admission coming from Rush is profound and cogent, IMO.