President Trump has 95% approval among Republicans.
Deal with that, Cindy.
Continued exposure to McCain’s positions did improve his standing with Republicans. As near as I can figure out his shtick was to meet the most left wing Dem on a given issue then put together a compromise to advance that issue with just enough Republicans that leadership could not block their compromise. These deals of his never advanced conservative priorities.
That McCain and his defenders would use his service in Vietnam as both a shield against criticism and a weapon against his critics annoyed more and more of his critics. What does service in Vietnam have to do with tax policy? to pick only one issue he was out of step with most Republicans.
There are a lot of reasons most Republicans went good riddance when he died.