Nobody knows what President Donald Trump meant when he threatened to “send in the Feds” if Mayor Rahm Emanuel can’t stop the “carnage” on Chicago streets, but if it means National Guard troops patrolling the streets of Chicago, everybody here seems dead-set against the idea.

Gov. Bruce Rauner says it would be a “mistake.” Emanuel says he’s “against it straight up.” Cardinal Blase Cupich said the violence he likened to the Great Chicago Fire is “more complex than that kind of solution.”

One South Side aldermen even went so far as to predict a “bloodbath” on Chicago streets if the National Guard is sent into inner city neighborhoods as an occupying force.

Emanuel said he welcomes a dramatically expanded partnership with the feds on a host of issues related to public safety.

They range from prosecuting gangs and gun crimes to investing in impoverished neighborhoods and reversing the precipitous decline in federal funding for summer jobs, after school and mentoring programs for at-risk youth.

But if Trump intends to send in National Guard troops, that’s where Emanuel plans to draw the line.

“I’m against it straight-up. … We’re going through a process of re-invigorating community policing. Building trust between the community and law enforcement. It’s antithetical to the spirit of what community policing is” to have the National Guard doing local policing, the mayor said.

“In dealing with gangs and guns, you want the federal resources that are set up to deal with that. That is ATF. That is DEA. That is the FBI. … The National Guard has nothing to do with public safety.”

Emanuel once again decried the “false debate” between those who deny there’s a “Ferguson effect” that has caused police officers to lay back for fear of being caught on the next YouTube video and those who argue that the “only alternative” is sending in the National Guard and returning to stop-and-frisk.

“You can’t just be rough and tough,” the mayor said.

In an appearance on WGN-AM Radio, Rauner stood shoulder-to-shoulder with his old friend the mayor.

“We continue to believe it’s not the right thing for us to send in the National Guard. That would be a mistake,” Rauner said, noting that he has bolstered State Police patrols on Chicago area expressways and has assigned State Police to help Chicago Police with forensics, investigations and lab work.

African-American aldermen were even more adamant about keeping the National Guard from becoming an occupying force in inner-city neighborhoods.

They argued that it would undermine the effort to rebuild public trust shattered by the police shooting of Laquan McDonald and the U.S. Justice Department’s scathing indictment of the Chicago Police Department triggered by that shooting. So much so that there could be a potentially dangerous backlash.

“For my communities, it would be an actual bloodbath,” said Ald. Toni Foulkes (16th), whose South Side ward includes crime-ridden Englewood.

“Look at what happened during the Boston Marathon, the curfews. We don’t know what will happen. When African-Americans think about the National Guard, we think about the prejudices and things like that.”

Ald. Ray Lopez (15th), whose ward includes gang-infested Brighton Park, called Trump’s threat to “send in the Feds” more of the same “political bluster” from the new president.

“The National Guard is using a hammer to kill a fly. We don’t need tanks rolling down Ashland Avenue. I don’t need tanks rolling down Archer Avenue,” Lopez said.

Before a City Council reception celebrating his recent elevation to cardinal, Cupich said he would welcome federal help to combat a violence problem he blamed on drugs, gangs, the easy availability of high-powered weapons and a shortage of jobs that has left young people “feeling that there’s no possibility for them. No hope.”

But, he, too, warned that the National Guard is not the answer.

“The problem is surely much more complex than that kind of a solution. … We have to make sure we don’t over-simplify this issue by just saying that it’s a matter of control by military or police forces,” the Cardinal said.

Chicago has “really wonderful police” who are “handicapped” by flood of guns and drugs and the shortage of jobs that leaves young people with “no hope,” the Cardinal said.

Even before the election, Ald. Pat O’Connor (40th), Emanuel’s floor leader, had argued that the City Council had made a mistake by picking a sign fight with Trump, who had a reputation for getting even and striking at at those who dared to criticize him.

Now, he fears he might have been right. The president’s tweet comes one day after Emanuel unloaded on Trump.

“This is who he is. This is what he’s gonna do. Just get used to it. This is a new way of being a president of the United States,” O’Connor said.

“If, in fact, it is a give-and-take or tit-for-tat, then I think we all better grow up.”

O’Connor acknowledged that, if Trump is determined to send in the National Guard, Chicago would be powerless to stop it.

But O’Connor said that is not what the city needs.

“For the president, I’m sure it would be a dramatic statement. But for us, it would probably be a terrible thing to happen,” he said.

“First of all, I don’t think it’s necessary. And second of all, I don’t think it’s what the average Chicagoan wants to see for their city.”

The Rev. Jesse Jackson said that Trump should work to address the root causes of violence “and not just callously make the observation.”

“If he has a plan, it can be redemptive,” Jackson said. “He’s using Chicago as a foil, [saying] ‘Look how bad they’re doing, I’ll stop it.’”

Jackson added that federal assistance could be helpful because “it is really beyond the scope of the city” to quell gun violence.

Over the years, there have been periodic calls by governors, senators and state legislators to send in the National Guard whenever the homicide rate in Chicago spikes.

Every time, the mayor of Chicago — whomever that happens to be — shoots down the idea.

The renewed threat comes at a time when Chicago’s image has already suffered from months of bashing by Trump and headlines touting the city as the murder capital of the nation.

The last thing that Emanuel needs — when he’s trying to build off a record year for domestic tourism and high-profile corporate relocations — is the indelible image of National Guard troops on the streets of Chicago.

It would send a message that Chicago is unsafe, out of control and a risk for both business and tourism.

The image of National Guard troops on the streets of Chicago would also conjure up ugly memories of the tensions that occurred during the 1968 riots and the Democratic National Convention, when Chicago Police officers and anti-Vietnam War protesters literally did battle on the streets of Chicago.

Contributing: Tina Sfondeles, Sam Charles