A Republican caller on Tuesday told C-SPAN that single mothers were responsible for taking America back to the "caveman age."

Paul, a Vietnam Veteran from Alaska, launched an attack on single mothers during C-SPAN’s Washington Journal, suggesting that liberals had relegated men to the role of sperm donors.

"For example, girls, 40 percent of the women now are without husbands to support their children," Paul said.

"That's regressive!" he exclaimed. "That's going back to the caveman age where men just bred women. And so, progressivism is regressivism."

The caller also opined that President Donald Trump was like the Vietnam War because "he's fighting the perception versus the reality."

As an example, Paul said that "the left, the greens are trying to sell the country that fossil fuels are bad and that we got to go solar and wind."

"We have to stay with fossil fuels or billions of people are going to die," the caller insisted. "The freedom of the world, the poor people are tied to cheap energy."

Paul warned that the U.S. was going to "lose the world" because liberals were against fossil fuels.

"There's item after item that the Republicans support versus what the left -- the progressives, which is actually regressive, see, because they're pushing us," Paul remarked.

Watch the video below.