I think this guy is right on the substance, but that doesn’t mean Bush doesn’t have a problem brewing:

The “ex-member of Bush’s base” wasn’t part of Bush’s base. He is one of the easily-angered, make-sure-you-find-something- not-conservative-enough-about-them, HowardDeanpersonality type conservative wing of the Republican party. They throw temper tantrums over side issues that affect life in America in the smallest ways and don’t want to vote for the candidates who on big issues are night/day different from the Democrats.
Bush’s base is made up of people who still so admire him as to actually call him not just a good, but a great president. There are MANY more of us, I am sure.