There have been three great American presidents during my lifetime, but each was fundamentally the same as the others: John Fitzgerald Kennedy, Ronald Reagan and Donald Trump. Not a racist bone in their bodies, each with a love of individual freedom coupled with a deep desire to defend our way of life, and anti-socialist to their very core.
Reagan once said that he had not left the Democratic Party, the Democratic Party had left him. I’m not sure that in voting Republican any time since the end of World War II that there has been any fundamental shift in the underlying philosophy of what that meant. But in voting Democrat, everything of substance has changed.
November 22 remains a date that I always notice, but one which fewer and fewer now do, even among those who personally remember that terrible day in Dallas.
Individuals make a difference. The Great Man theory of history is true so far as it goes, but there is only so much room anyone can manoeuvre. I don’t wish to be too political, but JFK could not survive in the Democratic Party as it has now become. Like Reagan and Trump, he would have had to become a Republican to have found a political home.
Law of Markets 
If memory serves, Reagan at one time confessed to being a supporter of FDR, he of the “New Deal.” So Reagan himself must have shifted position, though perhaps not as much as some believe — a source of libertarian contention.
In their own unique set of circumstances, each of these presidents only sought to improve upon the quality of life of their fellow citizens.