President Donald Trump amplified fears about his authoritarian ambitions by calling for the Illinois governor and Chicago mayor to be jailed as he deploys National Guard troops in the nation's third-largest city.

Troops from the Texas National Guard arrived Tuesday to assist in crackdowns on immigration and violent crime, but Gov. JB Pritzker vowed to challenge Trump's order and Mayor Brandon Johnson signed an executive order prohibiting U.S. Immigration and Customs Enforcement and other federal agencies from using city property for civil immigration enforcement.

The president, in response, called for both elected officials to be imprisoned.

"Chicago Mayor should be in jail for failing to protect Ice Officers!" Trump posted on Truth Social Wednesday morning. "Governor Pritzker also!"

Neither official has been accused of committing a crime, and both of them defiantly responded to his post.

"Trump is now calling for the arrest of elected representatives checking his power," Pritzker posted. "What else is left on the path to full-blown authoritarianism?"

"This is not the first time Trump has tried to have a Black man unjustly arrested," Johnson responded. "I'm not going anywhere."

Many other social media users also expressed alarm about the president's demand.

"The current President of the United States is militarizing our streets, creating a police state, and demanding the imprisonment of state & local elected officials he doesn’t like," posted former Republican congressman Joe Walsh. "Tell me again he isn’t a fascist. Go ahead."

"They are shooting ministers with pepper balls and the President is threatening to imprison a Governor," said Sen. Brian Schatz (D-HI). "There is no red line for these Republicans, even the good ones. They are gonna 'pick their spots' on the road to us becoming Belarus."

"Trump said this stuff all the time in the first term and people blew it off because DOJ ignored him," added former State Department spokesman Matthew Miller. "But with the Comey indictment and other investigations into his enemies list this term, have to take these threats deadly seriously. He means it, and so does the bureaucracy."

"If blue state governors and mayors aren't already thinking about the reliability of various police forces nominally under their control, they should start immediately," warned The American Prospect's Ryan Cooper.

"When Reuters (Reuters!) does the most straightforward, bloodless, nonpartisan headline possible and still comes up with ['Trump calls for jailing Democratic leaders as troops prepare for Chicago deployment']," noted Zeteo's Asawin Suebsaeng.

"If we’re drawing up a list of people who should be in jail..." mused journalist Mark Chadbourn.

"Donald Trump is calling for the Chicago mayor and Illinois governor to be locked up because they won’t bend the knee to his fascism and legitimize his lies and propaganda," wrote Democratic activist Melanie D’Arrigo. "Locking up political opponents to crush dissent is fascism, whether you like the word or not."

"The Trump administration is not just picking fights with blue states, the President is (again) threatening democracy," posted Rodger Payne, an international relations professor at the University of Louisville. "The leaders Trump wants to jail were elected democratically -- and unlike Trump, both easily exceeded support from over 50% of the electorate."