To our utter dismay, the National Association of Letter Carriers — the union representing the nation’s 290,000 active and retired postal workers, many of whom will handle millions of ballots as part of the massive vote-by-mail system — announced on Sept. 12 its endorsement of Vice President Kamala Harris for president.

As a result of the NALC endorsement, American voters are being asked to trust in an election system in which a key part of the process of casting and counting votes — specifically, mail-in ballots — is controlled by an organization loyal to one candidate.

Even back in Sept. 29, 2020, U.S. Rep. James Comer, R-Kentucky, a ranking member of the House Committee on Oversight and Reform, expressed concerns — similar to ours’ — about “the U.S. Postal Service’s strong reliance on highly partisan unions for election-related operations, including handling of ballots, and the risk it poses to Americans’ confidence in election results,” as reported in oversight.house.gov.

In a 2020 letter to Postmaster General Louis DeJoy, Comer called on the USPS “to ensure fair and efficient operations for the election and consider a program of monitors from the Republican and Democratic parties in postal facilities to help mitigate concerns,”  the website noted. He also requested information “regarding oversight of USPS’ employee mail-in ballot programs and the safeguards put in place to ensure compliance with federal ethics law.”

We remain skeptical about the USPS’ ability to do its job objectively with mail-in ballots and, instead, fear it just might try to rig the election.

Predictably, the Pew Research Center reported in July that “Republicans and Democrats continue to have vastly divergent views on vote-by-mail.” with 82 percent of Democrats saying it should be freely available without excuse — and only 37 percent of Republicans agreeing.

We urge all citizens who still believe its worth holding on to the principles of our constitutional republic  — established by the Founding Fathers  — to monitor the USPS, among other entities, to ensure a free and fair election on Nov. 5.

You can bet the farm on this one: In every future campaign, for any office, political strategists will prep candidates for campaign debates by having them watch one video and one video only: Kamala Harris’ performance against Donald Trump.

On Sept. 10, Harris not only destroyed Trump, she gave a master class in political debate. 

Rule #1: Prepare; do your homework.

Rule #2: Come armed with a clear message and, no matter what you’re asked, bang that message home. 

Rule #3: Figure out how to rattle your opponent and get under his skin. 

Rule #4: Relax. Smile. Stay Loose. Look like you’re having fun. 

On every one of those points, Kamala Harris delivered and Donald Trump did not. He was rattled, insulting, obnoxious and largely incoherent.

No doubt, Harris had done her homework. From the economy, to health care, to immigration, to Ukraine, to abortion, she knew the issues cold. She even offered a new plan to help families and small businesses. 

While Trump offered nothing but imposing more tariffs, which most economists warn would increase consumer prices. Amazingly, after eight years of promising to replace Obamacare with something better, he admitted he still didn’t have a new plan, just “concepts.”

Harris also came with a message and delivered it forcefully: Enough division, enough name-calling and personal insults, she repeated often, it’s time to “turn the page.” 

We already know what a mess Trump made of the presidency the first time, and “we’re not going back.” 

To which, as if on cue, all Trump could do was lie about his record, brag about getting more votes than any other Republican presidential candidate and still refuse to admit that Joe Biden got seven million more votes than he did.

And, boy, did Harris know how to get under Trump’s skin. It was the perfect cat-and-mouse game. 

Time after time, she baited the trap — and, every time, Trump walked into it: on John McCain; on his multiple felony convictions; on members of his own administration renouncing him; on foreign leaders laughing at him. 

But nowhere more so than when she talked about crowds leaving his campaign rallies early — in response to which Trump could only sputter and, with no evidence, accuse her of paying people to attend her rallies.

Through it all, Harris kept her cool. 

My advice: Go back and rewatch at least part of the debate with the sound off. Watch them side by side. You don’t have to hear what they’re saying to know who’s winning and who’s losing. She listens. She looks at him when she’s talking to him. She smiles or laughs out loud at some of the outrageous things he says. She’s having a good time. 

While Trump just glowers, never smiles once, looks tired, and clearly can’t wait to exit stage left.

In her opening remarks, Harris warned us we were going to hear a lot of lies from Trump. 

Still, nobody expected him to go as far as he did. Among his countless lies: Kamala Harris hates Israel; Joe Biden hates Kamala Harris; Harris will take your guns away; Harris still supports fracking; crime’s down everywhere in the world except here; Democrats support executing newborn children; and, my favorite, Haitian immigrants are stealing and eating cats and dogs in Springfield, Ohio. 

“They’re eating the pets,” he yelled.

After moderator David Muir pointed out that the city manager of Springfield told ABC News there was no truth to that charge, Trump supporters accused Muir and co-moderator Linsey Davis of unfairly fact-checking Trump three times. 

Ha! If they were really doing their jobs, they would have fact-checked him 300 times.

But Trump’s biggest lie was that women could trust him on reproductive rights. 

And that’s where Harris was at her best: destroying Trump by passionately pointing out that he was the one who killed Roe v. Wade and now brags about it and, if re- elected, would sign a national abortion ban (which Trump did not deny). 

She owns that issue.

Of course, one debate does not decide an election. If it did, after this week’s debate, this election would, and should, be over. 

But the debate did serve one important purpose: to prove to any of the 67.1 million watching who had not yet made up their minds that Kamala Harris is fit to be president on day one and that Donald Trump never was and is even less fit today.

On top of which, Taylor Swift’s endorsement is icing on the cake.