Politico's Anna Palmer and Jake Sherman report the U.S. Chamber of Commerce is "gearing up to challenge some House Republicans in primary elections" after "many of [the Chamber's] legislative priorities — immigration reform, the renewal of the Export-Import Bank and a long-term highway bill — have been held up by a clutch of conservative lawmakers in the House." It would be an unprecedented move, and even floating the idea suggests how determined the Chamber's national leadership is to fight for more immigrant labor and taxpayer-paid subsidies for business.

Chamber officials have not named any specific lawmakers they would like to take out, but if there ever is a list of targets, it would likely include the name of Iowa Republican Rep. Steve King, perhaps the most resolute opponent of comprehensive immigration reform in the House. (He's also against Ex-Im.) On Saturday, I asked King about the possibility the Chamber will challenge Republican incumbents who aren't on board with the business group's agenda.

"A handful of powerful interests in the U.S. Chamber demand cheap labor at any cost — as long as they are not paying the cost," King responded via email. "This [Politico] article reads like a policy of amnesty or bust. Amnesty begets anarchy."

"This isn't free enterprise," King continued. "They want to spend other people's money, and we know what Lady Thatcher said about those who spend other people's money."

If the Chamber is planning such a move, it hasn't made any announcement; the Politico report was sourced to "more than a half dozen Republican sources on K Street and Capitol Hill." Perhaps the whole thing is a trial balloon, launched by sources in the Chamber circle who want to test public reaction to the idea. Whatever the case, the plan, or threat, to primary opponents of comprehensive immigration reform and other Chamber priorities hasn't fully made its way around the House GOP world. "If that is happening, it is not something that crossed my path in any way," said a well-connected House Republican Saturday.

Others who know about the idea believe it would have completely the opposite effect of what the Chamber intends. "I think such a gambit would backfire," said one GOP member who asked not to be identified. "The Chamber has been successful defending K Street-centric Republicans from primary challenges, but if they tried to back a K Street Republican running as a challenger against a conservative incumbent, I think the Chamber support would be the kiss of death. The money they spend would effectively be an in-kind contribution to the conservative incumbent."

Whatever the case, the tensions that underlie the Chamber's thinking are not going to go away. And as far as Steve King is concerned, the bottom line is that a primary challenge strategy would just divide Republicans more than they are divided already. "The strategic division of the Republican Party only makes sense if you are a Democrat," King said.