Julie Sobel of the National Journal presents her list of the top five Senators who are vulnerable to primary challenges. If the list is reliable, primary challenges to Senators are unlikely to cause any seats to change from one party to the other.
The Senator most vulnerable to a primary is said to be Thad Cochran in Mississippi. It seems highly unlikely that the Republicans, who seem to have a solid alternative in state Sen. Chris McDaniel, will lose this seat if Cochran is defeated in the primary.
The second most vulnerable Senator supposedly is a Democrat, Brian Schatz of Hawaii. He faces a primary challenge from Rep. Colleen Hanabusa, who had hoped to be appointed to the seat when Daniel Inouye died. Either Democrat would be heavily favored to hold the seat for the Dems.
In Wyoming, Liz Cheney is challenging the incumbent, Michael Enzi. Sobel beleives that this challenge makes Enzi the third most vulnerable Senator. Neither of these two strong candidates would be likely to struggle in the general election.
I was happy to see that Lindsey Graham made the Journal’s list. He’s number four. I think it’s quite unlikely that Graham will lose his primary, but we can always hope. In any event, the Republican nominee should carry the state comfortably.
Last on the list is Mitch McConnell. His is the one seat of the five that could flip, and it’s possible that a McConnell defeat could cause it to. But if McConnell is even less vulnerable than Graham to a primary, then he may not be very vulnerable. We’ll see.
At this point, I should add this disclaimer: one can never be sure that a primary challenger, if successful, won’t self-destruct. As evidence, I cite Richard Mourdock. Few thought his primary victory over Richard Lugar would cost the Republicans a seat — I certainly didn’t — but that’s what happened because of a statement Mourdock made about abortion. Of course, an incumbent can similarly self-destruct (see George Allen), but that’s less likely because incumbents are more tested.
Finally, for perspective, let’s remember that in the past two cycles only three incumbent Senators — Lugar, Lisa Murkowski, and Robert Bennett — have lost in a primary. Lugar’s defeat cost the Republicans a seat, as we have seen. But Mike Lee kept Utah in the Republican column and Murkowski kept her seat by winning as a write-in candidate.
To the extent that primaries may have cost Republicans Senate seats in the past two cycles, this has occurred (with the one exception noted) in primaries that did not involve incumbents. It’s too early, I think, to speculate about whether or to what extent this will occur next year.