|Believe it or not, I've heard industry lobbyists say that they'd stop doing business in California/America if certain consumer protection regulations passed. It's totally implausible, but still a high-value card.|
Well, several businesses have followed through on that one in Malaysia or Indonesia (I forget which one). When they were forced to offer generic licenses for their HIV drugs, they stopped bringing in other new drugs for that country.
I think it's easier to do when you're "making an example" of a small enough market. No one would ever abandon California as a market, but they might crush a small Asian country to keep other countries from following suit...
Businesses don't even have to make that threat in person. The Chamber of Commerce, Republican Party, and other "pro-business" groups will always claim that this or that piece of legislation or lack of tax breaks shows your state isn't friendly toward business and will lead to an exodus of employers.
At the same time sports franchises have been very effective at playing the "I'LL Sail Away" card when blackmailing municipalities for new stadiums, parking facilities, zoning exemptions, and traffic revisions.
They even take this further, and play the "I'll sail away" card to obtain preferential treatment.