There is a solid psephological reason why Democrats should fear John Kasich.
In a first-past-the-post system like the United States, where the plurality winner of an election takes it all, parties have two strategies to win election. The first is base mobilization. The second is to appeal to the median voter. To some extent, these are contradictory: doing what you need to get the true believers to the polls reduces the party’s appeal to the median voter.
In presidential elections, both parties have tried versions of both appeals, but the GOP has relied more on base mobilization. Unfortunately for them, their base is shrinking in presidential electorates. Fortunately for them, however, they no longer need to worry about irritating their base.
Consider the below graph of popular vote margins in 22 swing states in the 2012 elections. Notice the asymmetry? The GOP won by a margin of 7.8% in its second-closest state, Georgia. That is a very large margin. A strategy that depressed its base would really only put North Carolina at risk, even with the demographic changes since 2012.
On the other hand, the Democrats won a lot of states by razor-thin margins. They won Florida (0.9%), Ohio (3.0%), Virginia (3.9%), Colorado (5.4%), Pennsylvania (5.4%), New Hampshire (5.6%), Iowa (5.8%), Nevada (6.7%), Wisconsin (6.9%) and Minnesota (7.7%) by smaller margins than with which the GOP won Georgia.
In other words, the GOP has nothing to lose by switching from a base-mobilization strategy to a median-voter strategy. Their primary electorate has made that difficult, however. One of the only two candidates with a moderate front besides Kasich has the unfortunate last name of Bush and an extreme record on reproductive rights. Kasich is no moderate on abortion, but he has two advantages over Jeb Bush. First, there is no Kasich equivalent of the Schiavo insanity that Governor Bush gave us. Second, most of Kasich’s anti-abortion positions are popular, or at least not unpopular. (The people on my email list may disagree with this, and I hope they chime in to explain why I am wrong.) Kasich may finally run into the wall with the bill in Ohio to ban abortions for fetuses with Downs Syndrome, but I would not count on it if I were a Democratic strategist.
Nor is he extreme on climate change. Oh, he probably will slow-walk the Clean Power Plan. (If anyone asks, I will explain what a GOP president could and could not do in another post.) But he won’t run on that, and inasmuch as people understand his position it won’t be unpopular: consider the recent vote in the California legislature. It stripped out the transportation mandates ... meaning the hard part of reducing Californian carbon emissions. And that was in the Golden State.
Add to that the fact that a Kasich candidacy takes a lot of base-mobilizing issues for Democrats off the table. Obamacare? Finally safe. (It is even if Bush or Rubio wins, but Kasich can credibly say that the battle is over once we are out of primary season.) Criminal justice reform? Check. Immigration? Well, Kasich has a problem with his calls to alter the 14th Amendment ... but let me be real. He can walk that back in the general. Latinos will not like him, but he is well-placed to pivot.
GOP doyens realize that they have reached the end of the base-mobilization strategy. Their problem is that they have settled on a candidate, Jeb Bush, who will have some serious trouble pivoting to a median-voter strategy. (In part, I think, this is because the doyens whom I have met have some very strange ideas about where the median voter lies in this country. To give a trite example, the non-Texan ones that I have met honestly think that “fat cat banker” is a powerful anti-capitalist epithet.)
What they do not realize, however, is that there is a pocketbook conservative on the ballot who really can swing median voters the old-fashioned way. And as Logan has argued, Donald Trump may be in the process of giving that candidate his shot.