John Kasich has a very narrow path to maximizing his chances for the Republican Presidential nomination (or a suitable consolation prize). However, it involves exercising self-restraint – and listening to the advice of that expert user of game theory, Mitt Romney.
Politicians can be excellent rational actors. This week, Mitt Romney urged Republican voters to support Ted Cruz. Previously, he suggested that Kasich and Rubio should only campaign in their home states, combining their support in each state. Do you suppose Romney really wants Cruz to be the nominee? Maybe…or maybe he just wants to prevent Donald Trump from getting a majority of delegates. Such an outcome helps Cruz, and it also helps Kasich…if Kasich does exactly the right thing.
In game theory, it is necessary to know what each player’s goals are, information and actions available to them at each decision point, and the payoffs for the various outcomes. In the case of the Republican nomination, we have the following information:
- Delegates are assigned to candidates according to state-by-state rules. They must vote for their assigned candidate on the first ballot, but after that they have the option to change their vote.
- A divided field lowers the threshold of voter support necessary to get a majority of delegates.
- If Donald Trump arrives at the convention with a majority of delegates, he will win on the first ballot.
- If Trump does not have a majority, his chances diminish considerably because of his outsider status.
Trump: It is in Trump’s interest for the field to remain divided. He may say that he wants a one-to-one showdown with Cruz. But in national surveys, GOP voters prefer Cruz over Trump by 15 percentage points. Broadly speaking, Trump can get 50% of delegates (or within a few dozen, which allows recruitment of uncommitted delegates) with as low as 35% popular support. So it is in his interest for Kasich to stay in the race in winner-take-all states. This was well worth the loss of Ohio’s 66 delegates. In fact, it was probably the cheapest way Trump could get that outcome.
Cruz: It is in Cruz’s interest for the field to narrow to a one-on-one race. For this reason, Cruz’s optimal actions last week were to campaign against Kasich in Ohio, and against Rubio in Florida. If Kasich drops out, Cruz could get 40% or more of total delegates. Therefore Cruz now wants Kasich to drop out – entirely.
Kasich: Kasich has no path to getting a majority of delegates. However, he does have a way to prevent Trump from getting a majority, which is different from what both Trump and Cruz want him to do.
First, Kasich should completely withdraw from winner-take-all states. Indeed, he should say so publicly, the way that Rubio pulled out of Ohio last week. In these states, he divides the “non-Trump” voter bloc, which polling suggests is about 55-60% of Republican voters. Therefore if Kasich does not drain support from Cruz, Cruz can take those states’ delegates away from Trump.
At the same time, Kasich should still campaign in the remaining proportional states, which are: Utah, the Northeast (New York, Connecticut, and Rhode Island), the Pacific Northwest (Oregon and Washington), and New Mexico.
Obviously, this path requires a lot of self-restraint. For one thing, Kasich doesn’t want Cruz to get the nomination. But I note that it is highly unlikely under any scenario for Cruz to get 50% of delegates.
Romney: Kasich’s strategy is exactly what Romney has recommended. Romney himself is carrying out the strategy – mostly. He advised Kasich and Rubio to pull out of one another’s home states. He campaigned for Kasich in Ohio. And now he is telling voters to rally around Cruz in Utah. This last step is not perfect – Romney could do even better by lying low in the proportional states.
In Romney’s case, we have the reverse problem. What is his eventual goal? It could simply be to stop Trump. But Romney may also be working in his own interest. An open convention also opens the possibility that Romney himself could emerge as the compromise candidate. After all, Romney does have a history of wanting to be President. The source of his credibility (former GOP nominee) is also grounds for suspecting his motives.
In graphical form, here is Kasich’s best strategy. The gray arrows indicate conventional political thinking.
Allowing a two-way race to unfold holds Trump to about 40% of delegates – and therefore an open convention. Cruz would also have approximately 40% of delegates, with Kasich and Rubio holding most of the remaining 20%. And the press gets the circus in Cleveland that it wants.