I don't think this analysis is correct. This unwavering support is true of Trump supporters today, but back in the run up to the 2016 there were definitely people who voted for Trump who would have changed their mind had the "grab them by the pussy" tape been immediately followed up by a media storm surrounding more awkward sexual allegations coming from from a porn star.

The Trump team clearly thought so - presidential campaigns are nothing if not obsessive about how optics can affect their candidates in key states, and by how much. The fact that they went to such lengths to cover it up was indicative of how impactful they feared it would be among swing voters.