Bush has $110 million, which he plans to spend:
Although Bush has no primary opponents, Republican advisers said he is preparing to unleash his war chest early next year, most likely against Dean. They described the former Vermont governor as the probable Democratic nominee and vulnerable to attack as liberal and inexperienced in security policy.
It’s worth pointing out that Bush, as governor of Texas, was inexperienced in security policy, though Cheney did have experience coming into the VP office. I’d argue that Bush’s experience since then has not been wholly successful. It is still possible for Dean to take the nomination and Clark to end up the VP candidate, which would certainly solve the security experience issue.