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A Texas businessman whose trade is in survival says the Trump administration has been a boon to his bottom line. Clyde Scott of Rising S Company in Texas says orders for survival shelters have doubled amid political uncertainty.

"During the Obama administration our sales went up 250 percent. In the Trump administration in the past month our sales probably went up 500 percent," Scott said in an interview with NBC News in February.

The underground bunkers are designed to help families wait out civil unrest, war, or natural disasters.

An 8-by-12-foot underground bunker sells for $45,000 — and that’s on the low end. The shelters have blast valves, air and water filtration and a stainless sink, toilet and shower. The smallest models are advertised as being able to store two years’ worth of food.

But some repeat customers said Trump was not the reason they are getting prepared. Josh and Brooke Greenhaw, who both voted for the president, were buying their second bunker.

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"Why not be prepared? It could be anything. It could be a tornado. It could be social unrest. Everything going on politically has really motivated me to want to purchase the bunker," Brooke Greenhaw said.

"We're not concerned about the Trump factor. It's the other people in the world we're concerned about," her husband said.

While Scott said sales of his survival bunkers have increased during the Trump administration, the "prepper" phenomenon is not new, and in modern popular culture goes back to fallout shelter amid fears of a nuclear attack during the Cold War. National Geographic’s “Doomsday Preppers” reality TV series launched in 2012 and ran for four seasons.

The New Yorker recently featured several Silicon Valley executives and other affluent preppers who have taken precautions ranging from laser eye surgery — glasses or contacts can be hard to come by in an emergency — to buying real estate outside urban areas to serve as a haven. Their fears ranged from civil war to natural disasters like a major earthquake.

The shelters Scott sells on the smallest end is an 8 by 12 mini bunker for around $40,000, while a 10 by 30 model that includes a shower and bullet resistant door is advertised at around $80,000. A “luxury shelter” like a 5,500-square-foot model can run into the millions.

"Someone's gonna be able to take his buddies in there and his friends. And they're going to be able to hang out and play pool, get in the hot tub. This one has an exercise room. It has everything," Scott said.

Scott says most of his customers are families who want, and can afford, the extra security.

"A husband, wife and two kids — that's really the typical client," Scott said.

Sales of shelters and bunkers have increased eight-fold across the board for Texas-based Norad Shelter Systems LLC, according to Walter McCarthy, Norad principal mechanical engineer.

"The biggest complaints from my customers are — one, Trump and his administration can't deal with facts," he told NBC News. "Second, because of that — the travel ban — and the lack of cooperation in other countries, we're not able to get intelligence we need to protect the country. Because of those two things, potential for war has increased many fold."

Ron Hubbard, owner of California-based Atlas Survival Shelters, says "There was an uptick two weeks before Trump’s election, and an uptick after the election. It lasted about a month."