Dear fellow Democrats:

To judge from the polls and personal experience, many of you are somewhere between lukewarm and ice cold toward Mayor Bill de Blasio. You love that crime keeps falling and that murders are headed for a record low, but worry that the growing disorder on the streets smells like trouble is coming.

You have never seen so many vagrants, and so many of them looking deranged and dangerous. Why didn’t he tackle the problem in the beginning, instead of denying the obvious — that the numbers were exploding?

You also don’t like it that the subways are a mess, traffic is pretty much congested everywhere all the time and bicycle riders are treated as privileged characters even as they routinely flaunt safety laws.

You pay the nation’s highest taxes, but it’s never enough. The cost of living here is out of control, despite what looks and feels like diminished public services.

Streets are filthy, roads are rutted, yet every time you turn around, City Hall is focused on race, gender and identity politics, as if that’s what working people care about most. Is the mayor really going to take down the Christopher Columbus statue in — of all places — Columbus Circle?

What would they call it — de Blasio Circle? Al Sharpton Circle?

Police are getting assassinated, jihadists threaten to destroy America — and City Hall honors a Puerto Rican terrorist.

You care about public schools, but the mayor’s claim of great progress sounds fishy. If graduation rates and test scores were so easy to fix, why didn’t it happen before? Are the numbers real, or are they faked to make the mayor look good? And why did he relax discipline standards, when every parent knows that one troublemaker can ruin a class for 30 kids?

Then there’s the mayor’s relentless war against charter schools, especially those that have a proven record of success. It feels immoral to sacrifice the future of at-risk children for the benefit of a union that is bloated with donations and political connections, yet de Blasio never misses an opportunity to create frictions instead of solutions.

His reflexive dishonesty is a big, big problem. The “city for sale” allegations ring true, and it’s not satisfying that just because the mayor skipped an indictment, he deserves a second term.

So as election season approaches, starting with next week’s primary, you’re not sure what to do. Then you read about de Blasio’s interview with New York magazine.

Your first thought is, it’s a miracle he didn’t break both arms patting himself on the back. Anyone reading his comments without living here would conclude that the Great Helmsman has single-handedly turned Gotham into the Garden of Eden.

Look at my record, he insisted, saying it deserved “parades out in the streets.” He boasted of “my policies and my leadership” and declared himself a great manager.

Me, me, me, my, my, my. It was tacky — and not at all reflective of the New York you live in.

Naturally, for anything wrong, it was “Don’t blame me.” He complained that a “tabloid culture” — The Post in particular — causes the “hateful, negative, divisive” public tone of politics, just before he denounced the rich, criticized Gov. Andrew Cuomo and tore into President Trump as “profoundly racist.”

It got worse from there. In comments to interviewer Chris Smith, the mayor dropped his re-election smiley face to reveal his inner dictator, one who would banish individual rights and constitutional safeguards — all in the name of fairness, as he defines it.

“Our legal system is structured to favor private property,” he said, insisting that “people would like to have the city government be able to determine which building goes where, how high it will be, who gets to live in it, what the rent will be.”

For good measure, he added: “If I had my druthers, the city government would determine every single plot of land, how development would proceed. And there would be very stringent requirements around income levels and rents. That’s a world I’d love to see.”

You certainly wish government could move faster and get things done with common sense, but the idea that Bill de Blasio and his corrupt crew would have the power to determine how every slice of land is used is unAmerican.

You have a house — suppose he wants to demolish it. Do you want him to have that power?

Then you realize, this is the progressive vision of government he’s always talking about, the idea that a select few should decide what is good for the rest of us and have the power to implement it. It is profoundly anti-democratic, yet that’s the world he wants to see.

Is that what a second term holds? Is he going to spring ideas like that after the election?

Beyond the arrogance, the mayor’s ignorance about American history and the Founders’ intent, as expressed in the Declaration of Independence’s guarantee of “life, liberty and the pursuit of happiness,” is appalling. Your children know better.

So what to do?

Here, my fellow Dem, is a modest proposal. Send him a message. Vote “no” in the primary by voting for someone else. Anyone else.

Whatever you do, just make it clear to de Blasio that you don’t approve of his message.

He’ll probably win anyway, but, hopefully, by a narrow margin. That would get his attention — and remind him of who’s the boss.

That alone would be a true public service for all New Yorkers.

‘Dream’ scream nonsense

Let me see if I have this right: President Trump is a rotten, dirty hater for throwing the “Dreamers” to the wolves by ending the program with plenty of time for Congress to find a solution. To judge from the overheated reaction, left, right and Barack Obama agree on this.

Color me curious.

Once upon a time, we had a government where Congress fulfilled its part in the checks-and-balances system. But gradually, and almost totally on many issues, lawmakers became expert only at ducking and kicking everything to the White House.

Because of that bipartisan cowardice, the estimated 800,000 Dreamers remained an unresolved issue for many years. Obama said repeatedly he couldn’t solve it, only Congress can write the laws.

Then, before the 2012 election, Obama changed his mind and, with a stroke of a pen, stopped deportations. But the “D” in DACA meant deferral, and everybody knew it was temporary and probably unconstitutional.

Congress, especially Republicans, was furious, and said it was their job.

So now Trump, after zigs and zags, calls their bluff. It’s your job, he said, now do it.

That’s what they wanted, and it’s how our system is supposed to work. So what’s the problem?

Lost in ‘left’ field

An email asks, “Do communists own the Democratic Party?”

Answer: No, they just rent it.

Hill hath foe fury

Headline: “Bitter Hillary blasts Sanders for ‘lasting damage.’ ”

Before she’s done, she will blame the whole world for her loss — everybody except herself.