It’s easy to feel Mayor Eric Adams’ pain: He’s huffing about how “unfair” it is that cities and states have to deal on their own with the “onslaught” of migrants streaming in. Too bad he won’t finger President Biden for refusing to 1) secure the border or even 2) handle the fallout.

It’s every city for itself, and New York’s generosity makes it a prime destination. Even Colorado’s Democratic Gov. Jared Polis is now sending migrants to New York and Chicago.

With shelters filled to the breaking point, and resources meant for native New Yorkers being spent on migrants, Adams pleads that “there’s no more room at the inn” — yet they keep coming.

“El Paso should not be going through this. Chicago should not be going through this. Houston, Washington, New York — no city should” have to decide whether to “provide for their citizens” or “deal with an onslaught of migrants,” rails Adams.

This is why that proud socialist, Sen. Bernie Sanders, used to be anti-immigration: No one can afford endless “free stuff” if the whole world can come for it.

On Tuesday, the mayor bluntly said, “The president has an obligation to deal with the immediate concerns.” The next day, he called on others to “critique the people who made this mess,” insisting: “I’m not going to sit back and allow New Yorkers to carry the burden of a manmade crisis.” How about naming the man who made it?

Not that Adams is the worst. Polis actually puffs: “We are honoring our values of treating people with dignity and respect.” Right, by “helping them” . . . get the heck out of Colorado and off his back.

Yet even Polis notes that “states and cities cannot continue to bear this burden alone.”

Biden now says he’ll finally visit the border next week — long after the crisis has spread nationwide. But if he doesn’t at last move to actually close it, he’s leaving Adams and other hard-hit mayors no choice but to start blasting him by name.