Well, I'll agree with him to this extent:

Parties need to be concerned with choosing candidates that are at least a baseline level of acceptable to the whole range of their usual voters.

Republicans have a big problem with that, because the biggest single segment of their base (at least 40%, probably more) wants Trump, and will be (pretty legitimately) upset / mutinous if the party tries to foist someone else on them. The rest of the party might hate Trump, but they have utterly failed to present an alternative that appeals to a bigger segment of their base than Trump's 40+%.

On the other side of the coin, the Democrats have issues with this also. Not as severe, but Hillary has a really high proportion of haters / mistrust even among registered Democrats.

Assuming Trump and Hillary are the final candidates, I hope that however it turns out there is a huge amount of blowback to *both* parties in terms of drastically higher numbers of people voting for 3rd party "also rans", write ins, or people otherwise clearly voicing their displeasure. Both parties have to do better than this pathetic set of choices.

Mutineer - Dad used to play that shit all the time.