Philadelphia and other American cities are facing trouble from the Trump administration over the issue of sanctuary cities.

New York, Chicago, Los Angeles and Philadelphia all fall into that category, though Mayor Kenney prefers to call ours a "Fourth Amendment City." The policy calls for non-cooperation with federal immigration authorities in detaining undocumented criminal suspects until the feds can deport them - unless they are convicted of a serious crime.

Trump wants to crack down on illegal immigrants and has threatened to use the power of executive order to deny federal funds to cities that follow the sanctuary concept.

Not to be undone, Pennsylvania's own U.S. Sen. Pat Toomey decided last week to reintroduce a bill he first advanced several years ago to punish sanctuary cities by cutting off their Community Block Development Grants, federal money that fosters subsidized housing and neighborhood revitalization programs. Philadelphia is getting $39 million in such grants this year.

What does a housing and redevelopment program have to do with illegal immigrants? Nothing.

The two are not related. What Toomey is proposing is the equivalent of stabbing a neighbor in retaliation for an argument you had with your mother. It doesn't make sense. The neighbor is an innocent bystander.

Politically, though, it does make sense for Toomey. First, it re-establishes his bona fides as an ultraconservative. He always has been one, but during this year's campaign, he tacked to the center, portraying himself as an independent-minded legislator who would, if need be, stand up to Trump. (You may also recall he refused to endorse Trump.)

Well, Trump won. And Toomey has to placate the soon-to-be president and his base.

Second, it gives a good reading of what he thinks of a city where 1.5 million of his constituents live. His bill could be the first wave of anti-city moves by the ruling Republicans. Republicans view cities as nuisances, not the essential economic engines that they are. They don't care whether the punitive steps they plan to take against immigrants and social programs hurt big cities the most. Most large cities are decidedly Democratic. (Toomey got 17 percent of the vote in Philadelphia in November.)

If Toomey wanted to be an advocate for all Pennsylvanians, he might use his position to act as a buffer - or perhaps a negotiator - over this federal-vs.-cities clash over immigrations. Instead, he is the first to draw the knife. Thanks, Senator.

There may be some buffer to stop Toomey's plan. The Supreme Court has intervened in these funding fights before and ruled that, while it is within its power for the federal government to deny funding to states, those actions must be "relevant." Also, the court has ruled that the federal actions cannot be "coercive." The federal action cannot be simply punishment for disagreements with the state. It has to justify the cuts.

Toomey's bill is almost a dictionary definition of irrelevant and coercive. In fairness to the senator, he has been on record for several years on his opposition to sanctuary cities. His bill failed last time because he could not get the 60 votes in the Senate to end a Democratic filibuster. Let's hope he fails again.

Still, we have to ask: Sen. Toomey, isn't there a better way to handle this issue than to stab one of your own cities in the back?