The trouble begins when politics overrules policy, especially bad policy.

That is the case with the immigration disaster that threatens to tear the Democrat Party — and the country — apart.

While big city Democratic mayors and governors are politically in lock step in their re-election support of President Joe Biden, they are at the same time hemorrhaging state taxpayers’ money taking care of migrants that Biden waved, and is waving, into the country. By the millions.

But because Democratic politics trumps Democratic policy — even progressive policy — they are loathe to criticize the president for opening the borders even as they go around pleading with him for money to deal with the migrants who are destabilizing their cities. How bizarre.

The latest is the example of big city mayors, all Democrats, begging Biden for federal dollars to deal with the uninvited “guests” from around the world who have swamped their cities.

Most recently three of those progressive mayors — Eric Adams of New York, Brandon Johnson of Chicago, and Mike Johnson of Denver — held a virtual news conference to warn that their cities, once sanctuary havens, were reaching full capacity.

They pressed for federal assistance. “All of our cities have reached a point where we are either close to capacity or nearly out of room,” Mayor Mike Johnson said.

Their whining came after Biden has repeatedly declined to meet with the mayors to discuss the problem, even as they have lavishly praised him. Mayor Adams can’t even get Biden on the phone, let alone meet with him.

In an earlier request for a meeting the mayors even thanked Biden “for your ongoing work and partnership regarding immigrants entering the United States via the Southwest Border.”

So far, the only “ongoing work” Biden has done at the Southwest Border is thrash all former President Donald Trump’s security initiatives and allow some seven to ten million immigrants from around the world to enter the country without permission, including some two million so-called “getaways.”

The numbers include unknown terrorists, criminals, and the drugs and weapons they bring with them.

Big cities like New York, Chicago, Denver, Los Angeles and others run by progressives cannot even deal with homeless American citizens.

Thanks to Biden and progressive Democratic policy, they are forced to deal with the influx of millions of poor people from around the world when they cannot even handle the unhoused and addicted Americans living on the streets.

Every thinking person knows that Biden’s progressive Democratic immigration policy destabilizing the country is a disaster. But Democratic politics prohibits them from saying so. Politics overrules policy.

That is why they avoid even mentioning Biden when they talk about the migrant surges, acting as though Biden has nothing to do with it. Instead, the criticize “the administration,” or “Washington,“ or “Congress,” but never Joe Biden.

They do not even mention the very practical idea of shutting the border down and having the migrants wait in Mexico for their chance to cross into the United States in a legal and orderly fashion.

Instead, they attack Republican Texas Gov. Greg Abbott for shipping migrants north to their once-welcoming sanctuary cities.

Abbott, who just signed a law allowing Texas law enforcement officials to arrest illegal immigrants and send them back to Mexico, has done more to secure the border than anyone else, including Biden. Especially Biden.

All of this brings us to Massachusetts Gov. Maura Healey, a progressive Democrat, who enthusiastically supports Biden politically even as his open borders policy has caused havoc with her administration and the state.

She, like the other progressives, blames “the administration” for the problem and not Joe Biden, the administrator.

And despite her support for Biden she, like the others, has also failed to get Biden to come up with substantial federal money to pay for the caring of the millions of immigrants he has let into the country.

“I’m committed to doing everything I can to reelect President Biden and Vice President Kamala Harris,” Healey said in a recent MassLive interview.

Good luck with that.

Peter Lucas is a veteran Massachusetts political reporter and columnist.

Gov. Maura Healey, with newly appointed Director of Emergency Assistance Lt. General Scott Rice, gives an update on the emergency family shelter program in October. (Nancy Lane/Boston Herald)