Just one day after Senator Thad Cochran of Mississippi voted for a deal to avert a default and reopen the government, the Club for Growth and the Senate Conservatives Fund endorsed his primary challenger for 2014, Chris McDaniel.
Such endorsements, of course, have spelled doom in the recent past for other Republicans who stepped out of line. The Club for Growth spent nearly $20 million in the 2012 election cycle, much of it on primary challenges to lawmakers not deemed sufficiently conservative. The Senate Conservatives Club spent $15 million that year, including spending big to help take out Senator Richard Lugar of Indiana. These two groups together were instrumental in putting Ted Cruz in the Senate, spending millions to help him defeat a more moderate Republican in the 2012 Texas GOP primary.
That's some serious money that can be arrayed against Republicans who are merely normal conservatives, as opposed to ideological purists. Thad Cochran may literally have ended have his career by doing the right thing.
Other senators didn't take the same risk. Among the 18 senators who voted against the deal were several otherwise reasonable people who face reelection in 2014. Charles Grassley of Iowa isn't up again until 2016, but this otherwise sensible conservative basically voted to let the U.S. federal government default and send the global economy into a freefall rather than face the wrath of a well-financed primary challenger.
Can you blame him? Well, yes you can. But it's no mystery why he did it.
We hear so often about how Republicans are driven right by the crazy Tea Party base and Rush Limbaugh. And, to be sure, that's a big part of the problem. But the main reason that well-financed incumbents like Cochran have to worry about retaliation for independent thinking is because of a small slice of super wealthy conservative and libertarian donors -- people like Peter Thiel -- who can finance primary challenges.
When the obituary of the modern conservative movement is written, a movement now self-destructing in the name of ideological purism, these donors will deserve a big share of the blame.