Speaking as Congress neared final approval of the historic tax bill, White House Press Secretary Sarah Sanders hailed the culmination of a year of major accomplishments. She cited the defeat of the Islamic State, the creation of 1.7 million new jobs, the lowest unemployment rate in 17 years, a rollback of excessive regulations, and more than 60 record highs of the stock market.

It is an impressive list, yet a catch was reflected in a question. Why, a reporter asked, in the face of such accomplishments, do polls show President Trump’s approval stuck at under 40 percent?

Sanders is good on her feet, and her answer was aggressive without being incendiary. She blamed the media for its lopsided coverage, saying it ignores accomplishments to focus on “other things” and echoed studies showing that 90 percent of TV coverage of Trump “has been negative.”

She’s absolutely right — in fact, she understated the bias that drives much of the anti-Trump coverage around the clock and around the country. And she’s right to hope that the tax bill’s help for families will help Trump’s standing in the polls.

But there’s more to the answer than media bias, and while Sanders can’t say it, I will.

Her boss remains his own biggest problem.

Trump has dug himself in a hole with large segments of the American public, and needs to step away from the shovel if he hopes to get out. A year in office, his accomplishments still are being overshadowed by bad habits and unlikable aspects of his personality.

Knowing that much of the media is out to get him, he should stop giving them ammunition. Most important, Trump must stop attacking individual Americans on Twitter.

His recent attack on New York Sen. Kirsten Gillibrand is a perfect case study. Trying to make a national name for herself, she’s aiming to galvanize the female vote by focusing on sexual harassment. So she attacked Trump over the allegations against him.

He responded, on Twitter, by calling her a “lightweight” and a “flunky for Chuck Schumer,” which are widely held views in New York political circles, including among Democrats.

But then Trump wrapped the rope around his own neck, saying she “would do anything” for campaign contributions. It was vague enough to let the jackals turn it into red meat.

The Washington Post called the line “sexually suggestive” and Gillibrand called it a “sexist smear.” The media piled on Trump and soon headlines appeared saying the incident had raised Gillibrand’s profile.

That’s a neat trick — in a few badly chosen words, Trump lifted her and made himself look small and mean.

While all Americans want a tough president, few want a mean one, even rhetorically.

In fairness, Trump has steadily gotten more disciplined, but there are still too many Twitter eruptions, making it hard to change public perceptions. Examples of his deep-seated problem are evident in the latest Quinnipiac poll, which shows voters disapprove by 59 to 37 percent of the way he is doing his job.

Although 63 percent say the economy is “excellent” or “good,” they give him a thumbs-down on his handling of the subject by seven points, with 51 percent disapproving and only 44 approving.

Many of those are “resistance” Democrats, of course, and they will never give Trump credit for anything. But I also believe he is being penalized for personal fouls by Americans who want him to succeed. They just need to be confident he’s not going to embarrass them five minutes after they say something nice to a pollster about him.

Other numbers in the survey reflect his deficit. He gets low grades on most character traits, from honesty to leadership, and only 28 percent think he is levelheaded.

Polls are not destiny, as Trump proved last year, and he worked with congressional leaders to keep 99 percent of Republicans on board for the tax reform despite those low approval numbers. No small feat, given his nasty battles with some of them.

But the stakes grow larger once the calendar turns. Republicans are facing an uphill fight to keep Congress next fall, and if either chamber flips, the anti-Trump knives will be in charge.

A Democratic House would probably push impeachment. If the Dems take the Senate, Trump’s reshaping of the federal courts would come to a stop. If the GOP loses both chambers, Katie bar the door.

Trump’s first year has been one of significant accomplishments, but the climb from here gets harder, not easier. If he can harness his combative instincts and keep his eye on the ball, he’ll have a chance to keep a GOP Congress for four years — and really have the chance to do great things for America.

It’s up to him.

Ignoring the le$$on

The dumbing down of standards isn’t limited to the classroom. The city’s Department of Education also grades itself on an easy curve.

Mayor de Blasio, in a gift to the unions, threw bags of money — actually, millions of bags of money — at 94 schools that were chronic failures instead of closing them.

Four years later, the verdict is in: Only 21 have made modest progress. That’s failure, but City Hall won’t admit it.

Educrats are closing only nine of those schools, plus five others, and are preparing to throw even more money at the rest, giving themselves yet another year to show results.

Here’s a better idea: Give the money and the students to the best charter schools. They have track records of producing excellence, not excuses and failure.

A Franken Quitshow

A Lily Tomlin line is appropriate: “No matter how cynical you get, it is impossible to keep up.”

The mysterious case of Sen. Al Franken’s “resignation” is Exhibit A. Pushed by more than 30 fellow Dems, the former funnyman said on Dec. 7 he would resign “in the coming weeks” over groping allegations.

It was, as a Wall Street Journal editorial noted, a strange speech. The Minnesotan declared himself innocent, said an ethics probe would vindicate him — but was quitting anyway.

Or was he? The timing vagueness was unusual — and intentional. His party wanted to get him out of the way quickly so it could contrast itself with GOP Alabama Senate candidate Roy Moore and President Trump, both of whom face sexual-harassment allegations.

Mission accomplished — partially, with Moore defeated five days later. But even cynicism can’t prepare you for times like these because a movement for Franken to rescind his resignation is now quietly underway.

Franken has been silent, and the governor of Minnesota, who already named a replacement, said he has received nothing official from Franken about a departure date.

Any more questions about why most Americans don’t trust Washington?

Iowa’s pain is NYC’s gain

Here’s one New Yorker’s definition of a good day: when Mayor de Blasio is out of town.

The Putz was in Iowa on Tuesday and even the weather in Gotham — a balmy 55 degrees and sunny — was celebrating.