What?
Gruber thought the American people were stupid. His entire ACA strategy was based on this. He wasn't astonished at all that the American people believed Obama.
Why on earth are we "defending" Gruber with this nonsense?
I believe the author is making a generalization of all the "Gruberesque" among the liberal, ivory tower elite.
They're so enlightened that it's hard for them to fathom how stupid the typical American is.