Earlier this week we saw Mitch McConnell come out with what seemed to amount to an open declaration of war on conservative upstarts. That came on the heels of the Big Money donor push in Alabama’s 1st congressional district on Tuesday. And now it looks like the pattern continues as yet another set of GOP donors sets its sights on someone they perceive as having caused the government shutdown… Michigan Congressman Justin Amash.

Business leaders are plotting to take down Rep. Justin Amash (R-Mich.) as part of a broader effort to punish lawmakers over the government shutdown.

In a letter obtained by The Hill, prominent Michigan donors request financial backing for Amash’s primary challenger, Brian Ellis. Seven individuals, including prominent Michigan businessmen Mark Bissell, J.C. Huizenga and Mike Jandernoa, signed the fundraising plea.

They argue that Amash “and others have effectively nullified the Republican majority in the U.S. House.”

“[Amash] and a small group of like-minded legislators rejected Speaker Boehner’s plea to pass legislation requiring Congress and the president be subject to ObamaCare, and put on hold the special new tax on medical equipment. This irresponsible action hurt over 50 great West Michigan businesses and was part of the chaos that led the nation to the edge of default,” the letter says.

The letter was printed on Ellis’s campaign stationery.

Don’t expect either Amash or his faithful supporters to get caught quite as flat footed as the folks in Alabama. Being the incumbent is a big advantage, and a number of donors – including sales giant Amway – are already lining up to say that they won’t be funding the challenger. Also, Freedomworks is getting into this early to stand up for Amash.

Conservative groups are aware of the challenge to Amash, are pledging to match the business community “punch-for-punch” to defend one of their champions in Congress.

“He’s the gold standard of principled constitutionalism in Congress,” said Dean Clancy, the vice president of public policy at FreedomWorks.

“We have heard that the K-Street establishment wants to knock him off — and we intend to defend him punch-for-punch.”

It’s way too early for predictions of an outcome, but one thing seems certain. This sort of a face-off is sure to take what should have been an uneventful, easy primary and reelection and turn it into a focal point for the national media and outside influence groups from both ends of the spectrum. Unlike other areas, though, it’s highly unlikely that this will open any sort of door for the Democrats. Whoever wins that primary should still be holding the seat after next autumn. But it’s sauce for the goose and will become one of the races to watch for 2014.