The conservative Weekly Standard’s editor Bill Kristol’s failed third-party candidate, David French, is now claiming presumptive Republican nominee Donald Trump’s campaign intimidated him not to run — but won’t provide evidence to support his allegation.

French, with little to no name recognition, is a staff writer for the conservative National Review and was tapped by Kristol to run as a third-party candidate to stop Trump in the general election.

French said on Tuesday during an appearance on MSNBC’s “Morning Joe” that Trump “unlocked something terrible in this country.”

French alleges someone from the Trump campaign called his wife’s family and said the “race would be very difficult for me.”

“Well, you know, it was probably one of the more ham-handed attempts at intimidation, which out of the Trump operation you can expect things to be done in most incompetent way possible,” French commented about the alleged phone call. “An individual calls — he says, ‘I’m sorry, but I’ve been asked by the Trump campaign to make sure that David knows this will be really, really bad for him.'”

French added that he didn’t know about the alleged phone call until after he had decided not to run.

“I assumed if I did this, look, I have been up against Trump for some time, and the assaults on my family have been overwhelming just as a writer,” French added, commenting on his critical writings about the real estate mogul. “As everyone knows, Trump has an online racist mob that he often stokes by retweeting some of these horrible white supremacists. As that online racist mob is fond of pointing out I have a multiracial family and so they have gone after my youngest daughter in the worst way imaginable.”

French, who adopted a child from Ethiopia with his wife, claims they have faced racial attacks.

“They attacked you for having a multiracial family?” MSNBC host Joe Scarborough questioned.

“Oh, you have no idea,” French responded.

The Trump campaign denied French’s allegation.

“There is absolutely no truth to this,” Trump’s spokesperson Hope Hicks told POLITICO, which also reported French hasn’t provided any evidence that the Trump campaign was behind the phone call.

Breitbart News asked French to provide evidence to support his allegation, but he has supplied none.