It would be more politically savvy of the party for him to die (of "natural causes") after winning the nomination, but before the convention. That way the Savior of the Party (either HRC or MO) can come in and take the nomination without having to go through the muckish primary contests.
The proggies would burn the convention down before HRC or MO would be substituted in.
It would be best for us if they can get the old fool to a doctor in time to save him should he keel over on the election trail. That way reality can set in with a vetting process without some sort of mythic messianic mandate taking hold worse than it already has. It would be better for the public, and better for the Democrats even, for this guy to be vetted. Then the pragmatists can take over the Democratic party and we can finally start moving forward.