It has been a watershed week for Republicans opposing their party’s nominee, Donald Trump.

Fifty GOP leaders released an open letter renouncing Trump on Monday, and Democratic nominee Hillary Clinton unveiled a Republican outreach initiative with several dozen officials who have crossed party lines to support her candidacy.

They are all oh-so-late to the game.

Sure, some top Republicans like Mitt Romney were ahead of this trend. But the true trailblazer is William F. Buckley, Jr., the founder of National Review magazine who’s often dubbed the father of modern conservatism.

Buckley weighed in 16 years ago when Trump was teasing a presidential bid on the Reform Party ticket.

In an essay for Cigar Aficionado titled “The Demagogues Are Running,” Buckley warned of a particular type of demagogy practiced by candidates like Trump, with the financial means, “personal or contrived,” to fund their own campaigns.

Look for the narcissist. The most obvious target in today’s lineup is, of course, Donald Trump. When he looks at a glass, he is mesmerized by its reflection. If Donald Trump were shaped a little differently, he would compete for Miss America. But whatever the depths of self-enchantment, the demagogue has to say something [to voters]. So what does Trump say? That he is a successful businessman and that that is what America needs in the Oval Office. There is some plausibility in this, though not much. The greatest deeds of American Presidents — midwifing the new republic; freeing the slaves; harnessing the energies and vision needed to win the Cold War — had little to do with a bottom line.

Buckley contrasted Trump with billionaire publisher Steve Forbes, who was funding his own Republican presidential campaign that year.

“Does it follow that all who finance their own campaigns are narcissists?” he asked. “Forbes is an evangelist, not an exhibitionist. In his long and sober private career, Steve Forbes never bought a casino, and if he had done so, he would not have called it Forbes’s Funhouse.”

“In the final analysis,” Buckley wrote, “the resistance to a corrupting demagogy should take first priority” for voters.

Buckley passed away in 2008. We don’t know how he’d feel about Trump’s run this time. But several months ago, the conservative magazine he founded ran the cover story below, and it’s fair to guess that if Buckley were around he would have nodded in agreement.