In an appearance Monday on the Christian televangelist network Daystar, conservative commentator Cal Thomas warned that the legalization of same-sex marriage undermines “all of human history” and poses a greater threat to America than Islamic extremists.

Responding to a question about “what can be done about the federal judges that override the majority of voters on marriage,” Thomas responded with apocalyptic warnings.

“Look at Mesopotamia. Look at the Roman Empire, which collapsed from within through moral impurity before they were conquered from without. And that’s my great fear. I don’t fear the Russians or the fundamentalist Muslims as much as I fear ourselves. We are committing moral suicide in this country: 55 million dead babies through abortion and counting, we’re mainstreaming same-sex marriage and the polygamists are right behind,” he said.

“You have the people who believe in adult-child marriage, they already do this in certain Muslim countries, these people want the rights as an adult to marry a child,” he added. “So all I’m asking, and what I do in debates is say, if the line has shifted now and we accept same-sex marriage, where would you then draw the line and on what basis? It’s all about the polls, feelings and the culture at the time, it’s not about established truth and real history.”