Every living president hates Trump, W. included. That doesn’t mean there is no trend.
There are historical events and reactions and counter-reactions to them that obviously bring us to a place that Americans would vote for Trump, first in the primary and then in the general election. I only object to the silly one-sided logic of Bush naturally led to Trump. The rejection of moderate respectable people like McCain and Romney also got us to this point.
Obama was a moderate and respectable person. Those moderate respectable people didn’t mobilize the Republican base. Trump did. That says something terrible about Republicans.