I have a rule about campaign "gaffes." If a candidate says something just once and if he'd take it back if you gave him the chance, then he ought to be forgiven. We all make slips of the tongue all the time, and they don't reveal some secret self that we've been trying to keep hidden. On the other hand, if a candidate says something repeatedly, especially even after he's been criticized for it, then it probably does represent a real sentiment that might tell you something important about him.

So when Donald Trump offered words of praise for Saddam Hussein at a rally on Tuesday, it wasn't exactly out of the blue.

"Saddam Hussein was a bad guy. Right? He was a bad guy, really bad guy," Trump said. "But you know what he did well? He killed terrorists. He did that so good. They didn't read them the rights — they didn't talk, they were a terrorist, it was over." The attention to this comment has been mostly context-free, not going much deeper than to note that Trump praised a bad man, which is bad. Trump has said this many times before, even presenting Saddam with the compliment of being politically incorrect: "Saddam Hussein killed terrorists," he said in February. "He didn't do it politically correct. He found a terrorist, they were gone within five seconds, OK. With us, we find a terrorist, it's going to be 25 years and a trial." Due process, what a drag.

But Saddam is not the only dictator whose brutal methods Trump admires. His fondness for Vladimir Putin (and vice-versa) is well known. Murderous man-child and lube enthusiast Kim Jong Un gets high marks from Trump for precociousness: "You gotta give him credit. How many young guys — he was like 26 or 25 when his father died — take over these tough generals, and all of a sudden... he goes in, he takes over, and he's the boss. It's incredible." About the Tiananmen Square massacre, in which the Chinese government crushed a budding pro-democracy movement, Trump said, "When the students poured into Tiananmen Square, the Chinese government almost blew it. Then they were vicious. They were horrible, but they put it down with strength. That shows you the power of strength."

Again and again, Trump seems to gaze in admiration at the savage methods of authoritarian governments and compare them unfavorably not only to our own leaders but to the legal and moral systems that keep us from acting in the same way. As he said about ISIS, "Can you imagine them sitting around the table or wherever they're eating their dinner, talking about the Americans don't do waterboarding and yet we chop off heads. They probably think we're weak, we're stupid, we don't know what we're doing, we have no leadership. You know, you have to fight fire with fire." Trump regularly advocates the use of not just the kind of torture that the Bush administration employed, but even more brutal methods, promising to "bring back a hell of a lot worse than waterboarding." And for what purpose? It isn't as though we're holding ISIS prisoners with knowledge of future plots we need to foil. Trump couldn't even say who he wants to torture and to what end; he just knows he wants to.

Now try to imagine that Donald Trump was president, and began acting on the impulses he puts on such proud display. He has said repeatedly that he'd like to "open up our libel laws" so that when people don't like the coverage they get in the media, they can sue news organizations more easily. What happens when he tries to intimidate journalists with something more than insults? What about when he orders members of the military to commit war crimes like killing the families of suspected terrorists, as he has suggested we ought to do?

An optimist might say that the institutions that have sustained our system for two centuries will stop him. "I still believe we have the institutions of government that would restrain someone who seeks to exceed their constitutional obligations," says John McCain — who, by the way, is supporting Trump. "We have a Congress. We have the Supreme Court. We're not Romania." Maybe not, but a great deal depends on the particular people Trump surrounds himself with.

All presidents chafe at the limits of their power, because all would prefer to be free to make the decisions they like without the meddling of Congress and the courts. These days, Republicans argue that Barack Obama has been a dictator, regularly exceeding the scope of his authority. But all of those disputes have been highly public and over questions like whether families should be broken up by deportation, or whether the Department of Health and Human Services' implementation of provisions in the Affordable Care Act adheres to the spirit and letter of the law on insurance subsidies.

Do we think that, if Donald Trump becomes president, those are the kinds of issues on which he'll test the limits of executive power? And we've been down this road before, with George W. Bush's administration after September 11. As Dick Cheney said less than a week after the attacks, "We also have to work, though, sort of the dark side, if you will... And so it's going to be vital for us to use any means at our disposal, basically, to achieve our objective." When Bush and Cheney decided that they wanted torturing prisoners to be one of the means at their disposal, did the system stop them? No, it did not, despite the fact that torture is illegal under both U.S. law and treaties to which the U.S. is a signatory. Lawyers in the administration were tasked with devising a rationale by which they could claim that they weren't actually torturing, and that's what they did, writing a series of memos claiming if the prisoner did not experience so much pain that he went into organ failure, then he wasn't actually being tortured (I realize that sounds like some kind of joke, but it's what they actually said).

As majestic as our institutions are, they didn't prevent that obscene affront to American law and values from taking place. I remind you of this recent history because for as much deserved criticism as George Bush received for his administration's contempt for constitutional principles, he was only restrained sporadically — and what he did is nothing compared to what Donald Trump quite clearly would like to do.

So when Trump talks about what a strong leader Putin is, or how eager he is to start torturing somebody, or what a great job Saddam did at preventing terrorism, it's not a "gaffe" and it's not something we can laugh off as Trump being Trump. It's all too clear how appealing he finds brutality, and how contemptuous he is of the laws and traditions that try to keep it under wraps. The system usually works to restrain the lawless and the corrupt, even in the highest of offices — but not always, and often not until great damage has been done.

If Donald Trump becomes president, we'll surely find out just how far it can be pushed.