Will Hurd said Florida Governor Ron DeSantis, his rival for the Republican presidential nomination, should take responsibility for a new state curriculum that calls for teaching that slavery gave enslaved people valuable skills.

“Implying that there is an upside to slavery is absolutely wrong,” said Hurd, a former US representative running a long-shot bid for the GOP nomination, in an interview Monday with Bloomberg Television’s “Balance of Power.”

DeSantis criticized Vice President Kamala Harris last week for going to Florida to condemn the recently adopted social studies curriculum. The Florida governor said he wasn’t involved in drafting the document but defended the standards.

“They’re probably going to show that some of the folks that eventually parlayed, you know, being a blacksmith into doing things later in life,” DeSantis said Friday.

“He shouldn’t have doubled down on this,” said Hurd, who has a Black father and White mother, and for a time was the only Black Republican in the US House.

“This could have been handled very, very easily by saying we’re going to tweak that language to make clear that slavery was a bad thing for our society, it was our original sin,” he said. “That’s what Ron DeSantis should do, and not pass the buck and say it wasn’t his responsibility.”

Hurd, 45, served three terms as a congressman from Texas after a career as a CIA spy and cybersecurity consultant.

He faces near-insurmountable obstacles to passing the first major test of the 2024 campaign: qualifying for the Aug. 23 debate in Milwaukee.

To participate, candidates need 40,000 unique donors and at least 1% support in at least three polls. Hurd hasn’t said how many donors he has and is polling at 0%. More importantly, he’s refused to sign a required pledge to support the eventual Republican nominee.

“I’m not going to sign the pledge — not because I don’t want to support the eventual nominee. I’m not going to support Donald Trump,” Hurd said during the interview. “And I can’t lie in order to get access to a microphone.”

Hurd has been a longtime critic of Trump, the Republican frontrunner, calling him a “lawless, selfish, failed politician” who would ensure a second term for President Joe Biden if he’s the nominee.

Hurd also criticized the Biden administration’s border policies, saying Monday’s lawsuit against Texas for putting a floating barrier in the Rio Grande River “is another example of how Joe Biden is getting border security wrong.”

Read more: Biden Administration Sues Texas Over Floating Border Barriers

He said Biden should seek a state and federal solution to the border crossings while working toward a more comprehensive overhaul of the immigration system.

Hurd, whose former congressional district ran 820 miles along the border, also opposed Trump’s border wall, calling it expensive and ineffective.