Registration for the March 17 Democratic presidential primary in Florida has closed. I and a number of other long-time Republicans have re-registered so we can vote for the candidate closest to the center with the best chance of winning the Democratic nomination and defeating Donald Trump in November. Hopefully, that choice will be clearer after Super Tuesday, but it looks like Joe Biden or Michael Bloomberg today.

I do not know how many we are. I do not know if we will make any difference. But I do know we must spare no effort in trying to exorcise the demon that has possessed the soul of the GOP.

There was a time when if you voted Republican, you had a pretty good idea of what you were voting for, even if you did not know the candidate. You were voting for fiscal discipline, cultural conservatism, an engaged, forward-leaning foreign policy, free trade, personal accountability, a commitment to the rule of law and the idea of America as a Shining City on the Hill to which the world looks for leadership and where the dreams, energy and genes of immigrants beckoned by that shining light are welcome. It was an optimistic vision of the future based on continuity with the past, however out of step with reality it may have been at times for many. It was Ronald Reagan’s Morning In America.

But that was then, and this is now. It was Trump’s genius to sense how pervasive is the moral rot within the GOP, something to which the establishment, including me, was for the most part oblivious. There has always been a seamy underbelly in the party, a sump where the paranoiacs, conspiracy theorists, radicals and racists pooled, whether it was the John Birchers in the 1950s who believed President Dwight Eisenhower was a communist or the right wing populists today who believe the late Sen. John McCain was a traitor. Historically, this 25 percent to 35 percent minority was flattered and exploited during campaigns, paid lip service after election day and not taken very seriously most the time.

As recently as the 2006 Republican gubernatorial primary it was safe to ignore them. In that race, Tom Gallagher, the early favorite, had re-invented himself as a champion of the religious right, which was another iteration of the persistent populist phenomenon in the GOP, just as movement conservatives and the tea partiers were other iterations. The gravitational pull to the right on Charlie Crist, Gallagher’s opponent, was powerful. I and others urged Crist not to eat the poison candy of extremism, to stay close to the center with the general election in mind. Crist did not take the bait, and he defeated Gallagher by a 2 to 1 margin and went on to win the general election easily.

In the years that followed, the political calculus fundamentally changed. Economic disruption and distress caused by the global transition from an industrial economy to a service economy intensified and spread. Rapid cultural changes roiled society. The continuing browning of America heightened white fright, which the Obama presidency exacerbated. And wars that could not be won did not end. In this pressure cooker of anger, angst and envy, what had been a fairly small, fairly stable minority in the GOP metastasized. The tail became the dog.

And Trump seized the moment. In doing so, he did not so much transform the GOP as unmask it. It is no longer Morning in America. The optimism is gone. Damn the future. Let’s go back. Make America Great Again. But great when?

Reactionary, isolationist, protectionist, nativist, small-minded, mean-spirited and redolent with racism, the Trump GOP is better suited to the 1930s than to tomorrow, right down to the America First slogan borrowed from that era. And while Trump is as much an effect as the cause of what I believe to be an existential crisis for American representative democracy, he is the accelerant that daily feeds the fires of division and dissolution.

So I am going to vote in a Democratic primary for the first time in 40 years. For many of my like-minded acquaintances it will be for the first time ever. It may all be for naught, but duty calls nonetheless.

Mac Stipanovich was chief of staff to former Gov. Bob Martinez and a long-time Republican strategist and lobbyist. He has since registered as no party affiliation and as a Democrat, and his voter registration now varies with the election cycle.