On Monday, members of the Electoral College will gather in each state to select a president. We call on them, particularly Republican electors, to deny Donald Trump the presidency — as the Constitution allows and as the Founding Fathers envisioned for a candidate so antithetical to their aspirations for the nation's highest office.

We do not ask this lightly. We realize that millions of people, including many of our readers, voted for Mr. Trump. Some liked him or embraced his stances on issues. Others saw him as a change from business as usual, or wanted to send a message, or just didn't like Democrat Hillary Clinton or the other alternatives.

And we realize that passions are high and such a move by the Electoral College would further inflame them.

Yet this is precisely what the founders of our republic envisioned when they devised the Electoral College, a singular body with a singular purpose: to afford, as Alexander Hamilton explained to the people of New York in Federalist No. 68, "a moral certainty, that the office of President will never fall to the lot of any man who is not in an eminent degree endowed with the requisite qualifications."

Mr. Hamilton almost seems to have anticipated Mr. Trump, a rich developer and reality show host with a flair for publicity, in defending a process designed to guard against someone with "Talents for low intrigue, and the little arts of popularity."

Mr. Trump certainly is endowed with those. A TV ratings magnet, he won with no small help from near-constant media coverage. Now, at a time when he should be getting down to the serious business of preparing for the most powerful and sensitive job on Earth, he blows off intelligence briefings and jets around the country for campaign-style rallies, as if to feed an insatiable narcissism. He draws deeply from the military to build what has always been a largely civilian cabinet. He picks an education secretary hostile to public education, an energy secretary known for forgetting the name of the very agency he is to lead, a national security adviser who spreads false conspiracy theories, a secretary of state with business dealings with Russia, and a top White House strategist whose internet site caters to anti-government white nationalists.

It's as if Mr. Trump sees this all as entertainment — the more controversial his appointments and nominations are, the better his ratings.

To be clear: This is not about ideology we disagree with. A president is entitled to push his agenda. This is about Mr. Trump's inability, as far as we can tell, to take this seriously. To rise to all the presidency represents.

Americans have been waiting for Mr. Trump to "pivot" — away from the bombast, the insults, the lies, the bigotry, the attacks on the free press that have long been the mark of despots. Instead, he continues to provoke domestic and international concern — attacking those who disagree with him, toying with the anxieties of major powers like India and China, and continuing to lie, even over something as patently false as his claim to have won a historic landslide. (In fact, it was one of the narrower races in U.S. history.)

A man with so little regard for truth and the demands, dignity and responsibility of the presidency must not be given the awesome power of commander in chief of America's armed forces, or access to its nuclear arsenal.

Mr. Hamilton also explained that the Electoral College was a shield against foreign influence, as much a concern today as then. Mr. Trump has done nothing to assuage unease about the fact that he and his family have interests abroad that would pose conflicts for him as president.

Thursday was, in fact, the day Mr. Trump had promised to announce how he would resolve those conflicts. He abruptly postponed that to January. Given his lack of transparency throughout the campaign, there is every reason to suspect he has no more intention of shedding his conflicts than he has of ever releasing the tax returns that might reveal them.

This is no mere formality. Any continued dealings with foreign states could qualify Mr. Trump for impeachment the moment he takes the oath of office. In putting this issue off to January, he has left the Electoral College with no idea if he would enter the presidency in violation of the Constitution he would swear to uphold.

In calling on the Electoral College to reject Mr. Trump, we have no expectation that electors will choose Mrs. Clinton, whom we endorsed, though an argument could be made for defaulting to the candidate who so decisively won the popular vote. Perhaps they could choose a compromise candidate from the Republican Party, such as Gov. John Kasich of Ohio, or House Speaker Paul Ryan of Wisconsin. Or electors could simply deny Mr. Trump the 270 votes he needs; then, the Constitution specifies, the president would be elected by the House of Representatives.

Whatever choice they make, we beseech them to see that there is one thing that separates a demagogue from a despot, a bigot from a tyrant, a chaotic candidacy from a disastrous presidency: power. To grant it to Mr. Trump is to put our republic in peril.

Our nation's founders understood both the benefits and risks of democracy, and wisely built a safety valve into our Constitution. If there was ever a moment to use it, it is now.