Until last year, I was as Republican as you could get. My family had belonged to the GOP since the 1850s, and both my grandfathers labored in local Republican politics. I started volunteering for the party nearly a half century ago, handing out Nixon pamphlets in Saratoga Springs, N.Y., at the age of 13. I went on to work for Republican politicians in the New York State Legislature and both houses of Congress. And for a couple of years, I served in the research department of the Republican National Committee.

But early in the morning of Nov. 9, shortly after Trump claimed victory in the presidential election, I took out my laptop and changed my registration to independent.

From the start of the campaign, I knew that I could never vote for such a person. Trump is a mashup of all the sorriest parts of Republican history: Herbert Hoover’s trade policy, Warren Harding’s incompetence, Charles Lindbergh’s dictator worship, and Joseph McCarthy’s dishonesty. Still, until election night, I was hoping that that he would lose, and that the GOP could rebuild itself. This hope died as big states tipped into his column. It was painfully evident that the Trump brand would stick to the party for years.

And it really was painful. It has become commonplace to say that the parties are “tribal.” The term is apt. Especially for people who have worked in campaigns and government staffs, a party is a social network. Many of my friendships grew out of winning together and losing together in Republican politics. I still count these people as friends — and hope that the feeling is mutual — but the election cut an important connection.

I don’t disparage those who voted for Trump. Economic change has left millions of working Americans behind. They think that an increasingly affluent professional class pushes them around. Voting for Trump was a way to push back. I get it. My father was a milkman in a college town. It was full of people with advanced degrees who looked down on people like us.

Some of the resentments underlying the Trump victory had helped propel Ronald Reagan to the White House. But Reagan was more than a vessel for indignation. He stood for something. In his "Evil Empire” speech, he showed moral clarity about our country’s struggle with Moscow. He warned against “the temptation of blithely declaring yourselves above it all and label both sides equally at fault … and thereby remove yourself from the struggle between right and wrong and good and evil.”

Those words represented the Republican Party at its best. By nominating Donald Trump, the GOP chose its worst. During an interview, Bill O’Reilly pointed out that Vladimir Putin is a killer. “There are a lot of killers,” Trump replied. “You think our country's so innocent?” That comment was not an outlier. Whereas Reagan spoke of America as a shining city on a hill, Trump has dismissed American exceptionalism, saying, “I don’t think it’s a very nice term.” In rejecting Reagan, Trump aligned himself with Putin’s words: “It is extremely dangerous to encourage people to see themselves as exceptional, whatever the motivation.”

Of course, the GOP was not always at its best. During Watergate, Republicans learned about Nixon’s dark impulses and crimes. But as the scandal unfolded, key party figures declined to march in lockstep. Months before the “smoking gun” tape came to light, Sen. James Buckley of New York called for Nixon’s resignation. He wrote: “Inevitably the president is the focus, the essence of the crisis of the regime; the linchpin of its entire structure. It could not be otherwise. The character of a regime always reflects and expresses the character of its leader.”

Republicans don’t talk that way anymore. As Trump’s presidency confirms some of the worst fears of his critics, most party leaders are either defending him or expressing vague concern without holding him to account. House Speaker Paul Ryan backed the firing of FBI Director James Comey. In response to the news that Trump had spilled secrets to the Russians, Senate Majority Leader Mitch McConnell merely called for “a little less drama.”

Kneeling to Trump, some are reversing long-held positions. The most egregious example is Newt Gingrich. In 1993, he helped shepherd the North American Free Trade Agreement through the House. Twenty years later, he called for comprehensive immigration reform: “As a party, we simply cannot continue with immigration rhetoric that in 2012 became catastrophic — in large part because it was not grounded in reality.” Now he has embraced Trump’s stands on both issues.

As Ronald Reagan said of his journey from Democrat to Republican: “I didn't leave my party; my party left me.”

John J. Pitney, Jr. is a professor of government at Claremont McKenna College. Follow him on Twitter @jpitney