Stupid question. We don’t live in a vacuum. Issues change, people learn, and positions mature. The issues Ronald Reagan supported today would likely be different from the issues he supported 35 years ago. As those issues were different from the ones he supported 35 years before that.
All true. It doesn't stop people from asking the question though, even when it comes to long-dead figures like Jefferson, Lincoln, FDR, and JFK. It's more a way of making a political argument than a serious attempt to answer unanswerable questions.