While progressives and their media allies are consumed by alternate bouts of hysteria and disbelief, Donald Trump is doing what they assured Americans was unthinkable: following through on his campaign promises. And nowhere has that follow-though been more pronounced than his efforts to combat illegal immigration.

“On Wednesday, the president ordered Executive Branch agencies ‘to deploy all lawful means to secure the Nation’s southern border,’ which includes the ‘construction of a physical wall on the southern border,’” National Review reported. Trump also laid the groundwork for empowering the DHS and the DOJ to crack down on sanctuary cities and hiring 5,000 additional Border Patrol agents along with 10,000 more ICE agents who will be given expanded authority to detain and deport illegals.

Their reaction? “Morale amongst our agents and officers has increased exponentially,” a joint statement from the National Border Patrol Council and National ICE Council declared.

One of the more impressive aspects of these developments is the reversal of the Obama administration’s odious “catch and release” policy. Trump’s directive requires border agents to deal with illegals at the border instead of releasing them into America with a summons to appear in U.S. immigration courts in the future — one spanning more than three years due to immigration court backlogs, undoubtedly exacerbating an already embarrassing reality: the vast majority of illegals never show up for their court hearings.

Obama’s “fix?” During the previous administration, DHS ultimately ordered agents not to arrest illegals at all, thereby eliminating the need to show up in court, according to congressional testimony given last February by Brandon Judd, president of the National Border Patrol Council.

With regard to genuine refugees, Trump will insist on the “proper application” of the William Wilberforce Trafficking Victims Protection Reauthorization Act of 2008. The Obama administration had used the act as pretext for dispersing unaccompanied alien children “refugees” throughout the country, even though they weren’t unaccompanied or trafficked — meaning they weren’t really refugees.

Lastly, Border Patrol Chief Mark Morgan, a political appointee who clashed with the Border Patrol union and favored “comprehensive immigration reform,” was ousted.

Unsurprisingly, Trump’s determination to build the wall — and his insistence Mexico will pay for it “one way or another,” as Press Secretary Sean Spicer put it — precipitated the cancellation of a meeting this week between Trump and an angry Mexican President Enrique Pena Nieto.

That anger rings quite hollow. In 2005, Mexico published booklets instructing illegals how to enter America safely and remain there undetected. In 2014, Nieto and former Guatemalan President Otto Perez Molina signed the Southern Border Program to Improve Passage agreement, allowing Guatemalans to travel legally through Mexico to facilitate their illegal entry into the United States.

Americans should keep both realities in mind when the media complain Trump is “humiliating” Mexico.

And while leftist’ upheaval regarding the wall and the border will be intense, it will be tame compared to their reaction with regard to Trump’s efforts against cities, states, college campuses and countless other entities that have declared themselves illegal alien-harboring “sanctuaries.” Nothing epitomizes leftists’ contemptible contention that they can ignore any law they don’t like more than these self-declared fiefdoms in unambiguous defiance of federal immigration statues.

Aside from defunding these sanctuaries, Trump’s additional initiatives include the restoration of the 287g program “permitting designated officers to perform immigration law enforcement functions,” re-instituting the Secure Communities program (killed by Obama in 2014) linking people booked into local jails with federal immigration authorities, and cutting off visas for countries refusing to take back citizens deported by the United States.

That cutoff is critical. A 2001 U.S. Supreme Court ruling prohibiting ICE from detaining anyone ordered to be deported longer than six months precipitated the release of hundreds of thousands of criminal aliens onto the streets of America — including convicted murderers, sexual offenders and kidnappers — when defiant nations refused to take back their own citizens.

Countenancing this outrage was standard operating procedure for the Obama administration. No longer.

Yet perhaps the most effective idea for dealing with sanctuary entities is the simplest. First, some context. As Fox News reported in 2015, “Government agencies that crunch crime numbers are utterly unable — or unwilling — to pinpoint for the public how many illegal immigrants are arrested within U.S. borders each year.”

Unable? In her book, “Adios America,” Ann Coulter made it caustically clear that keeping a lid on the data was wholly intentional. “You will spend more time trying to obtain basic crime statistics about immigrants in America than trying to sign up for ObamaCare,” she explained.

Trump will eviscerate that blackout by publishing “a comprehensive list of criminal actions committed by aliens and any jurisdiction that ignored or otherwise failed to honor any detainers with respect to such aliens.” The policy, dubbed “Name and Shame” by The Washington Times, is utterly anathema to progressives who treasure an uninformed public. One that can be cowed by accusations of bigotry and nativism, or conned by assertions that illegal immigrants are vital to the fabric of American society.

Considering the level of public outrage stoked by a single incident — the murder of Kate Steinle by Juan Francsico Lopez-Sanchez, a seven-time convicted felon deported five times and released to the street by the San Francisco Sheriff’s Department instead of being held for ICE — it doesn’t take much imagination to envision what a steady diet of news about similar outrages would engender.

Another idea the Trump administration could explore might even be more effective, because it frames an argument (something the Right isn’t particularly adept at) and because it would impact those directly responsible for maintaining sanctuary policies. Right now the Steinle family is pursuing a federal lawsuit against San Francisco, former Sheriff Ross Mirkarimi, the U.S. Bureau of Land Management (BLM) and U.S. Immigration and Customs Enforcement for complicity in the death of their daughter.

Yet even if the Steinles are successful, taxpayers would be paying for any judgment in their favor. Perhaps it’s time a GOP-controlled Congress explored the idea of making politicians and law enforcement officials who defy federal immigration law directly responsible for the consequences of that defiance. Those who would elevate the concerns of illegal immigrants over their fellow Americans — putting Americans in wholly avoidable harm’s way as a result — deserve nothing less.

Apparently some progressives are already getting the message that Trump means business. Miami-Dade County Mayor Carlos Gimenez has ordered jails to comply with ICE detainment orders. Miami-Dade receives about $355 million in federal funding.

Expect similar surrenders in numerous other locations when progressive outrage gives way to fiscal reality. Expect resistance as well, engendered by those long used to arrogantly defying the law, absent serious consequences. It won’t last long. Realize it or not, they have met their match.

“From here on out, I’m asking all of you to enforce the laws of the United States of America — they will be enforced, and enforced strongly,” Trump told the assemblage of officials at DHS headquarters. “We do not need new laws. We will work within the existing system and framework.”

It’s about time.