Back in May 2023, co-blogger Kevin Corcoran posted on Randy Holcombe’s discussion of how people form preferences on  government policies. Kevin quoted Randy as follows:

The Republican party, at least since Ronald Reagan’s presidency, supported free trade, but after President Trump won on a protectionist platform aimed at China, Mexico, and other countries, most Republicans did not push back and argue that Trump’s protectionist policies were out of step with the party’s values. Rather, they supported Trump’s trade policies.

This quote is from Randall G. Holcombe, Following Their Leaders: Political Preferences and Public Policy, Cambridge University Press, 2023. Kevin wrote:

These are voters whose beliefs about free trade were simply a derivative preference, derived from their anchor preference of identification with the Republican party. When the Republican party advocated free trade, so did they. And when the Republican party turned away from free trade, so did they. In the same way, after Trump’s rise to prominence in the Republican party, support for free trade among Democrats shot up dramatically, to significantly higher levels than Republican support for free trade during the presidency of George W. Bush.

I don’t disagree with this reasoning. I think there’s lot to it. But I do want to point out a counterexample. Back in 2021, Trump revealed to his supporters that he got a booster for the COVID-19 vaccine. A fair number of them booed. So they didn’t adjust their views based on the guy that many of them seemed to love.

Of course you could argue that they can’t adjust their views instantly. It’s quite conceivable that many of them thought that Trump wouldn’t get a booster and thus, in their view, be “on their side.” So they might have booed out of surprise. Still, a fair number of them had to know that he had done Operation Warp Speed to get the original vaccine produced quickly. If they had adjusted their views of the vaccine to what they must have thought his view was, they would have been in favor. But a fair number of members of the audience, going by the volume, saw him as being wrong on this.