Ronald Reagan told one of the first CPAC gatherings in 1974: "We cannot escape our destiny, nor should we try to do so. The leadership of the free world was thrust upon us two centuries ago in that little hall of Philadelphia".
Quoting Pope Pius XII after World War II, Reagan said, "Into the hands of America, God has placed the destinies of an afflicted mankind."
Contrast that with what President Donald Trump said on Saturday when he addressed the Conservative Political Action Conference. Trump's speech, coupled with the appearance a day earlier by White House chief strategist Stephen Bannon, provided the most definitive articulation of the "America First" philosophy that is redefining conservatism and, with it, the Republican Party.
"The core conviction of our movement is that we are a nation that put and will put its own citizens first," Trump said. "For too long, we've traded away our jobs to other countries. So terrible. We've defended other nations' borders while leaving ours wide open."
Reagan's speech in 1974, along with his frequent later appearances at CPAC, was an evocation of his vision of America as a shining city on a hill and "the last best hope of man on Earth". His vision called for an outward-looking America, a nation whose unique power and position carried with it obligations to the rest of the world.
Trump, the economic nationalist, said: "There is no such thing as a global anthem, a global currency or a global flag. This is the United States of America that I'm representing. I'm not representing the globe. I'm representing your country."
Reagan was not a believer in global government or handing powers to international bodies like the United Nations. Reagan espoused American exceptionalism and a nation seeking to defend freedom around the world. Trump looks inward and appears to begrudge the responsibilities of leading the world that previous presidents have embraced.
It is commonly asserted that Trump and Trumpism have buried Reagan and Reaganism, that the conservatism of the past few decades is rapidly being replaced by a mixture of policies that range across the ideological spectrum, some of which are directly contrary to what conservatives have long espoused. That assertion of the takeover is mostly true.
The speed with which the transformation of the Republican Party is taking place is breathtaking, at least on the surface. Many conservative intellectuals remain holdouts, but rank-and-file Republicans so far are enthusiastic, and Trump's hardcore supporters are ecstatic.
Trump is still a work in progress. His speech at CPAC sounded much like his campaign speeches, replete with promises yet to be fulfilled. His supporters give him credit for keeping those promises, as the first weeks of his Administration have been a projection of his intention to do just that.
The details of his promises remain sketchy. Some of his agenda is conventional conservatism as it has been defined since and even before Reagan. Domestically he's for lower taxes and less regulation to spur business activity and economic growth.
Bannon used a phrase that perhaps sounded ominous to describe the struggle to enact this agenda. He called it the "deconstruction of the administrative state". In less grandiose language, it represents an effort to pare back the federal government. Republicans long have advocated exactly that.
Trump's advocacy of these policies is one big reason so many traditional conservatives, and particularly Republican elected officials, are making their peace with a president whose candidacy they opposed and whose language and style repelled them throughout the 2016 election.
Trump and Reagan shared something else. Each sought to redefine the Republican Party as one that was open and welcoming to working-class Americans, many of them longtime Democratic voters.
Trump and Bannon would argue that the world is far different than it was when Reagan came to power. The Soviet Union, with which Reagan battled, no longer exists.
Trump sees Russia as a potential ally against Isis, but Russia's interference in the election casts a shadow over Trump's presidency, and Trump's gentleness toward an aggressive Russian President Vladimir Putin is anathema to Reaganites.