GHWB voted for Hillary, Jeb and W. voted for neither Hillary nor Trump (meaning that they either wrote in Jeb or voted for Bill Kristol's little Mormon puppet Evan McMullin).
So strong was the Bush clan's feeling of entitlement to the White House and their allegiance to the political establishment that they were ready to hand Hillary the Presidency out of spite towards Trump. If anyone still thought that the Bushes were decent people, that should have been the last nail in the coffin.
Yet they had no qualms about telling conservative voters to support them, because any third party vote would just be "helping the Democrats." Apparently, loyalty is for little people, not for the royal family of the GOP establishment.
The most important thing to the Bush family was preserving their 30 year bipartisan policy of non-enforcement of immigration laws and borders.