Donald Trump has already promised voters that as president he would create a special federal “deportation force” that would round up and summarily deport suspected illegal immigrants. Now, in a remarkable interview with Yahoo News, published Thursday, the billionaire former reality television star, who is leading in many Republican presidential polls, further clarified his grand vision of turning the U.S. into a police state.

In the aftermath of the ISIS-orchestrated terror attacks in Paris last week, Trump moved quickly to stoke and then exploit the fear of such an attack on U.S. soil. ISIS, which controls territory in Syria and Iraq, has displaced millions of Syrian civilians, a tiny fraction of whom the Obama administration has pledged to shelter in the U.S.

Related: Terror on the Cheap – The Challenge of the ISIS Paris Massacre

Trump, however, has been warning in near-hysteric terms that, “refugees are pouring into our great country from Syria,” a claim that is wildly wrong. On Thursday, he latched on to a thinly sourced report about eight Syrians being “apprehended” at the southern border, taking to Instagram to warn that “they could be ISIS.”

Later reports from the Border Patrol confirmed that two Syrian families, two men, two women, and four children, had presented themselves voluntarily to border guards near Laredo, Texas.

Trump’s campaign -- literally from the moment he announced it by claiming that the Mexican government is sending rapists and murderers into the U.S. -- has been based on a combination of whipping up fear of some shadowy outside force bent on harming “real” Americans, alleging the existence of an additional threat in the form of some sort of fifth column inside the country, and then offering himself as the great protector who will stand in its way.

There’s powerful historical precedent for people coming to power in that way. Google it. It always ends badly.

Related: Can ISIS Save the Russian Economy for Putin?

With the alleged Mexican threat, Trump simply offered to build a “big, beautiful wall” on the Mexican border. (His deportation force, in all its dystopian awfulness, is an absurd fiction. To keep Trump’s promise to get rid of all 12 million undocumented immigrants in the U.S. in the space of two years, he would have to oversee the deportation of nearly 16,500 people every single day.) But now that he has turned his focus to ISIS, Trump’s promises and plans have become more insidious.

Trump had already said publicly that the U.S. ought to establish a vigorous surveillance program to oversee mosques in the U.S., and even suggested that the government might have to close down some mosques.

In his interview with Yahoo, though, he outlined further steps that he believes might need to be taken against U.S. citizens and legal residents who happen to be Muslim.

“We’re going to have to do things that we never did before,” Trump told Yahoo’s Hunter Walker. “And some people are going to be upset about it, but I think that now everybody is feeling that security is going to rule. And certain things will be done that we never thought would happen in this country in terms of information and learning about the enemy. And so we’re going to have to do certain things that were frankly unthinkable a year ago.”

Related: Jeb Bush – We Need U.S. Ground Troops to Fight ISIS

Walker asked Trump if that might include subjecting Muslims to warrantless searches. Trump refused to rule that out. What about creating a database with the names of all known Muslims in the U.S., or forcing Muslims to carry a special identification card? Trump refused to rule that out either.

“We’re going to have to look at a lot of things very closely,” Trump said.

It’s a shame Walker didn’t see if Trump would be in favor of forcing Muslims to affix yellow crescent moon patches to the outside of their clothing. It would have been clarifying.