My Momma always told me that if you don't have anything nice to say don't say anything at all*. Notice the difference
Blinder said that one should blast disagreement to the media, Holtz-Eakin said you "support the policy the candidate's chosen." Blinder's position is consistent with keeping one's mouth shut unless specifically asked (and maybe refusing to answer if asked or even maybe maybe dodging the question if asked).
Holtz-Eakin clearly feels obliged to say things he doesn't believe. I mean it isn't clear from the quoted passage, but it is clear from his general record.
* (and you can just imagine how frustrating it could be to try to tell that to me -- I don't recall her ever losing her temper over the issue -- my momma is a saint)