LLS
It doesn't seem to have been an issue among the viable Repubican candidates thus far. Change tax policy to favor retaining domestic employment, that's an easy one. There is a growing contingent that sees nothing wrong with tarriffs to disadvantage imports. That's dangerous ground, historically, even though that's what funded the federal government entirely right up to the twentieth century.
Casting blame doesn't solve anything and is easily countered. Offer solutions, conservative ones, or get badly beaten up on this particular issue. There is deepseated anger, as I mentioned, and allowing Democrats to capitalize upon it when they're more the cause will be a mistake.
You say it won't stand in the general election unless Romney is the nominee. I say, as it stands, it'll be avoided by all but Ron Paul, and having a libertarian streak a mile wide, I'm not entirely certain that he'll have anything to say that resonates with and capitalizes upon the populist anger.
BS or not, they're capitalizing. It's naive to think it won't be a powerful means of persuasion for many. It keeps modern day Reagan Democrats on the plantation, for one thing.