It’s understandable that he would be irked by the SCF. Aside from McConnell, the SCF is targeting Hill veterans Thad Cochran of Mississippi (in Congress since 1973) and Pat Roberts of Kansas (since 1981). Speaking to CNN, former NRSC communications director and GOP strategist Brian Walsh lamented the SCF’s history of “propping up weak candidates and attacking Republicans under the banner of conservative purity so they can line their own pockets.”

It’s true the SCF has helped oust establishment favorites only to have their candidates go on to underperform or become national embarrassments, notably Ken Buck in Colorado and Christine “I’m not a witch” O’Donnell in Delaware. On the flip side, there have been a number of underwhelming NRSC-supported candidates in recent years—see Connie Mack in Florida, Tommy Thompson in Wisconsin, and Rick Berg in North Dakota. And the list of SCF-endorsed candidates who triumphed over national GOP opposition in recent elections is a who’s who of party superstars: Marco Rubio, Rand Paul, Ted Cruz, and Mike Lee.

This brings us to the May 13 primary for the open Senate seat in Nebraska, where the NRSC’s meddling is particularly hard to justify. The two top Republicans are Ben Sasse and Shane Osborn. Both men are impressive. Sasse is a fifth-generation Nebraskan and Yale Ph.D. He worked for Boston Consulting Group and McKinsey & Company, specializing in crisis management and turnaround projects. Just after 9/11, he worked in the Justice Department’s Office of Legal Policy. Later in the Bush administration, Sasse was an assistant secretary of Health and Human Services, where he worked on initiatives to rein in entitlement spending and modernize health care, and acquired a reputation as a formidable health policy expert. He moved back to his hometown of Fremont, Nebraska, to become president of Midland College. In the last four years, Sasse rescued the college from bankruptcy, gained national attention for his tenure reforms, and doubled the college’s enrollment.