I dunno but that website OP linked is a well known right wing propaganda “polling aggregator” that only takes pro-trump polls. I wish they had just linked the washington post article or an archive link thereof instead.
The call to remove the presumptive candidate is an entirely different thing than saying "and put our chosen person in instead". If he said a specific person you'd criticize him for trying to decide for the whole party.
The replacement should be chosen after consideration by a much broader group, either behind closed doors by party leadership if it's Harris, or by the delegates if it's not (or they simply don't think directly installing her is the best move).