Reagan the Actor had very different politics than Reagan the Candidate.
Check out his stump speech for Truman[1]. Quick highlight quote:
“Remember that promise: a real increase in income for everybody. But what actually happened? The profits of corporations have doubled, while workers wages have increased by only one-quarter. In other words, profits have gone up four times as much as wages, and the small increase workers did receive was was more than eaten up by rising prices, which have also bored into their savings” - Somehow Ronald Reagan
It's almost as if people will advocate for their own interests, and if their interests change, so too does their advocacy. As the SAG leader, he would obviously advocate for more money for himself and his fellow actors, saying whatever rhetoric he needed to, and when he was president, he would similar advocate for whatever keeps him further in office.
So he got smarter on economics as he aged like most people? His economics advisors were at the top of their fields, including Nobel laureates. It is not highly shocking that he changed his views.
Check out his stump speech for Truman[1]. Quick highlight quote:
“Remember that promise: a real increase in income for everybody. But what actually happened? The profits of corporations have doubled, while workers wages have increased by only one-quarter. In other words, profits have gone up four times as much as wages, and the small increase workers did receive was was more than eaten up by rising prices, which have also bored into their savings” - Somehow Ronald Reagan
[1]https://youtu.be/uJDhS4oUm0M