Donald Trump’s signature campaign promises -- deport all undocumented immigrants, ban Muslims from entering the U.S., build a wall on the Mexican-American border -- are cruel, unjust and racist.

And beyond violating the basic moral precepts that many believe lie at the core of America, they would devastate the U.S. economy.

Let’s start with the wall Trump wants to build between the U.S. and Mexico. Trade across the border accounts for $1 billion in economic activity every single day, supporting 6 million American jobs. In other words, no matter who pays for it, the cost of constructing Trump’s fantasy divider between the two countries is insignificant compared to the cost America would pay if trade with Mexico were drastically decreased.

Even worse is Trump’s promise to deport all 11 million undocumented immigrants. Some 6.8 million of them are workers, and forcibly removing them would leave an estimated $381.5 -$623.2 billion hole in the U.S. economy. Just how big a deal is that? It would cut private gross domestic product by 2.9 percent to 4.7 percent. In other words, Trump would singlehandedly and voluntarily throw the economy into a very bad recession.

But, of course, it doesn’t end there. Banning all Muslims would cost the U.S., at a very minimum, around $24 billion a year, Marketplace reported. Of course, it is hard to estimate the cost of such a draconian policy. And economic costs are not even the greatest toll.

“The first and foremost cost is it’s going to flush the Bill of Rights on day one of any potential Trump presidency,” Corey Saylor of the Council on American Islamic Relations told Marketplace. That assessment is applicable to Trump’s other immigration policies as well.

It’s not just Trump’s central policies that would pitch the U.S. economy needlessly into a recession. The presumptive Republican nominee has a whole second tier of terrible ideas-in-waiting, just idling in the background.

Take his promise to trash all the U.S.’s trade pacts. “If Mr Trump did even half of what he has promised, he would surely set off the worst trade war since the Great Depression,” former U.S. Treasury Secretary Larry Summers wrote in the Financial Times. When you’re using the Great Depression as a yardstick to assess economic policy, things have pretty clearly gone wrong.

“Trade war” is not a term most people are familiar with, but it basically amounts to the U.S. and, say, China slapping ever-higher tariffs on goods coming from the other country, causing markets to plummet and the global economy to slow.

There’s also the gold standard, to which Trump gives a thumbs up.

The gold standard might sound good -- who, especially Donald Trump, doesn’t love gold and standards? -- but it’s one of the worst economic ideas ever. This is a harebrained policy that no other country uses and not a single surveyed economist thinks is a good idea. (The Trump campaign did not respond to a request for comment for this article.)

Under the gold standard, a dollar is worth a certain amount of gold. And since gold is a commodity whose price swings wildly, a central bank like the Federal Reserve would have to raise and cut interest rates based not on how well the economy is doing, but on what’s going on in the gold market.

It’s a good way to run a modern economy into the ground. In other words, it fits in nicely with Trump’s other economic plans.

Editor's note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims -- 1.6 billion members of an entire religion -- from entering the U.S.