When Democrats lose a presidential election, they think the president is literally Hitler and that the sky is going to fall. Republicans don't do that.
That applies to both sides, this is an absurd claim. Republicans hated Obama after he was elected and for 8 years.
Trump is a unique case and the hate is strong but George W. Bush had a 90% approval rating after 9/11 and was easily re-elected. It was only deep in his second term when Democrats turned strongly against him (along with many Republicans).