The Etch A Sketch fiasco was especially damaging because it fed into a pre-existing narrative about Romney’s lack of core convictions, and because Romney’s Republican opponents picked it up and ran with it. But I don’t think it has the indelible power of Dukakis riding in the tank with a big-ass helmet and a goofy grin. I think Romney’s bigger problem is that he’s really set things up so that he will pay an inordinate price every time he contradicts a position he has previously taken, whether that position was taken in 1994, 2002, 2008, or during this year’s primaries. There’s a cost to any flip-flop. But there’s a huge cost to a flip-flop-flip. And once you gain a reputation for shifting your positions, you no longer can shift positions for political advantage.
Imagine what would happen, for example, if Romney wrapped up the nomination and then decided to come out as pro-choice. That’s only the biggest example, but on many less resonant issues, Romney has locked himself into a right-wing position that doesn’t poll well with the general electorate.
Romney can look at all the public opinion surveys he wants to discover where he needs to be on the issues, but those surveys can’t measure the cost to people’s perception of his integrity when he pivots off a position he took to appeal to the Republican base.