A single line jumped out at me as I looked at the New York Times article on Donald J. Trump’s view of the U.S. Constitution.

Adam Liptak’s story goes through a litany of concerns that constitutional scholars — across the political spectrum — have expressed about the presumptive Republican presidential nominee’s views.

Then he writes of Trump: “He has threatened to sic federal regulators on his critics.”

That sentence stopped me cold. I froze.

Do you remember what happened to the last president who decided to “sic federal regulators on his critics”?

If you don’t, I’ll remind you.

President Richard Nixon did that very thing, we learned during the congressional investigation of the Watergate constitutional crisis.

http://www.nytimes.com/2016/06/04/us/politics/donald-trump-constitution-power.html?hp&action=click&pgtype=Homepage&clickSource=story-heading&module=first-column-region&region=top-news&WT.nav=top-news

That revelation — along with many others — led the House Judiciary Committee to approve articles of impeachment against the president, who then resigned his office on Aug. 9, 1974, thus ending, in the words of his successor, President Gerald Ford, “our long national nightmare.”

Trump wants to make it easier to sue the media for libel; he wants to ban Muslims from entering the United States; he attacked a federal judge solely on the basis of his ethnicity, calling the American-born jurist “a Mexican” who, according to Trump, “hates me.”

Any one of those occurrences would be a recipe for a top-of-the-line constitutional crisis. I’m trying to imagine what could happen if more than one of those things ever were to occur if a President Trump were to settle in behind that big desk in the Oval Office.

Here’s a comment from a conservative thinker, taken from Liptak’s article: “David Post, a retired law professor who now writes for the Volokh Conspiracy, a conservative-leaning law blog, said those comments had crossed a line.

“’This is how authoritarianism starts, with a president who does not respect the judiciary,’ Mr. Post said. ‘You can criticize the judicial system, you can criticize individual cases, you can criticize individual judges. But the president has to be clear that the law is the law and that he enforces the law. That is his constitutional obligation.’”

I believe this is a major part of what Hillary Rodham Clinton said Thursday when she described Trump as being “temperamentally unfit” to become president of the United States.