Just when you think that the race for the Republican presidential nomination could not get any more cruel and unusual, the party plays the next card off the bottom of the czazy deck.

Remember when Rick Perry got in trouble for correctly pointed out that bigots would deny immgrant youth an education don’t “have a heart”? Things turned so ugly that Perry had to come out for heartlessness.

Now, Mitt Romney is in trouble for opposing Chinese currency manipulation that harms the US economy.

Romney’s otherwise lame economic plan featured robust criticism of China for its money machinations. Indeed, Romney called for a “Reagan economic zone” of countries that don’t manipulate their currency.

That did not sit well with the Club for Growth, the exceptionally well-financed conservative pressure group that takes bushels of money from Wall Street speculators—who, of course, like nothing better than a little currency manipulation.

The Club for Growth is fretting about the fact that Romney’s plan has some similarity in focus and language to legislation proposed by Democratic senators Sherrod Brown of Ohio and Chuck Schumer of New York that would impose duties on China if that economic powerhouse fails to allow the value of its currency to float, rather than keeping it pegged to the value of the dollar—a policy that creates great pressure on US businesses to offshore operations from the industrial heartland and set up shop in Asia.

The Club for Growth has made beating the Brown-Schumer bill a top priority, as it would defend US economic interests by allowing federal officials to place tariffs on goods from countries that manipulate their currency rates in order to dominate export markets

Currency manipulation achieves many ends for the Chinese government and the corporate interests with which it has aligned: wages are depressed in the United States and China. Corporations that are willing to play one country against another come out ahead. And speculators make a boatland of money.

These goals are all so appealing to the Club for Growth that the group has now made the stance of GOP presidential candidates on the question of whether to crack down on currency manipulation an official “litmus test.”

“Voters deserve to know where the Republican candidates stand on the important issue of trade with China,” chirps Club for Growth President Chris Chocola. “Would each candidate, as president, sign the Schumer-Brown legislation to make it easier to impose tariffs on Chinese imports? What do they say to arguments that imposing tariffs would be devastating to economic growth and would harm America’s recovery? What do they say to arguments that starting a trade war with China would kill jobs, not create them? Americans deserve to know which, if any, presidential candidates side with Senator Schumer and Senator Brown.”

Actually, every presidential candidate should side with Schumer and Brown, as Republicans who worry about protecting US jobs and industries such as South Carolina Senator Lindsey Graham and Maine Senator Olympia Snowe already do.

But that won’t happen, because there are some presidential contenders who are more indebted to the Club for Growth and China than they are to US workers and communities

Give the Club for Growth some credit here. By making this issue a litmus test, they are forcing Republican presidential contenders into making “Which Side Are You On?” choices.

Will Rick Perry start talking about the virtues of currency manipulation in order to distinguish himself from Romney?

Will Romney backtrack and say that it is heartless to oppose current manipulation?

Will we see Michele Bachmann try to revive her campaign by repositioning from “R-Minnesota” to “R-China”?

Will Herman Cain come up with a plan to lower pizza prices by delivering them to US homes from China? (Will Chris Christie order Herman Cain’s pizzas?)

The Club for Growth is a ridiculously influential group in the Republican Party because it throws around ridiculously large amounts of money to back the interests of its paymasters, er, contributors.

Now, we’re going to find out if the Club can make the Republican presidential contenders embrace its ridiculousness.

Best bet? Yes, they can.