Many mayors of major US cities are claiming that they were not implement some of President-elect Trump's orders regarding deportation. Would the police be obligated to listen to the mayor and ignore the president or would they be obligated to listen to the president and ignore the mayor?
Do United States Police Officers Answer to the President Before the Mayor?
No. In some cities, e.g. New York City, they don't answer to either. Although the mayor can fire and replace the police commissioner there, individual officers are not obliged to obey the mayor. In other cities, the head of the police may be elected separately from the mayor. And the president isn't connected to local police at all.
That said, they do have to comply with the law. And if the law requires them to do certain things in certain situations, then they have to follow that. Even in those places where the police are directly under mayoral control, the mayor can't force them to break the law. E.g. the mayor can't demand an extra-judicial hanging. Or force them to ignore immigration law.
The current battle seems to be being fought mostly in terms of funding. The federal government is sending certain monies to the city. It may stop sending some funds to cities that don't do certain things. Cities are defiantly saying that they'll continue even in the face of loss of funds. Note how this hits two Republican issues: immigration and cutting spending. And a very small number of Republicans live in those cities. As such, don't be surprised if the funding is in fact cut.
There are 2 facets of this - are they required, and can they be compelled even if they are not:
Strictly speaking, there is currently no law which requires state police to participate in immigration enforcement per se.
As another answer noted, municipal law enforcement officers (LEOs) are basically employees of municipal government, and as such (unless they hold an elected office like the Sheriff
of Nottingham) they report to the Mayor, NOT to federal executive branch/President.
However, there are ways that they can be persuaded to follow the law:
Direct financial dependency on federal government.
Between FY2009 and FY2014, the federal government provided nearly $18 billion dollars in funds and resources to support programs that provide equipment and tactical resources to state and local LEAs (Source: White House).
Additionally, local LEO recieve much more indirect support (intelligence, training, liason, federal info) as well.
Threat of federal prosecution
Purely theoretically, illegal immigration is a crime. I'm not sure if it's legally feasible (I'll ask on law.se) but there may be a possibility that LEO who "harbors" an illegal alien may be prosecuted for aiding and abetting or (if it's organized) conspiracy. IINALADPOOI, so this is just a random guess that may not be feasible legally or practically.
As another answer noted, financial pressure can be put on the city rulers and the Mayor directly.
Federal government typically has a lot of money they can threaten to cut off to the city, if the city is defiant.
There are also secondary considerations (awarding contracts, etc...).
Last but not least, with sufficient votes, Congress can theoretically even pass a law making it an explicit crime for local LEOs not to enforce immigration law. Not sure how feasible that is in practice as far as getting enough votes, and of course it would have to survive constitutional challenge that is inevitable to arise.
You should note that police force has a different chain of command from military force whose top commander is the Commander-in-Chief, President of the US.
Police officers are to follow orders from Mayors who appoint the top police officer called chief of police/police commissioner/superintendent/sheriff. In other words, the commander-in-chief of police officers in each city and county are mayors. (Depending on the size and relevant laws of each city and county, it might work differently.)
Mayors don't follow orders from the President. They follow the law. If they are found not to follow any law, they can be recalled and sued by city council members or citizens depending on the law.
Theoretically, mayors don't have to follow the President's initiatives and policies. However, the federal government has some power to force their initiatives and policies through incentives and disincentives (stick and carrot). Cities and counties rely on support from state and federal government and mayors need to receive as much support from the federal government as possible, one good example of which is infrastructure projects which cost a lot of money. The federal government has ways and means to control mayors. It's always give and take and that's politics.
We will see how many mayors can defy Trump's policies when they become reality. There will be some reasonable middle ground that each side could agree on. That's what I expect to happen.
First, except in DC there is no direct connection between local or state government or law enforcement and any branch of the Federal government. Federal officials have more power because the Federal government is larger and has more people, money, lawyers and guns, not because they directly report to someone that is in the Federal government.
Some local law enforcement officers, Sherrifs for instance, may not have a superior that they report to — there is no one that can give them orders and fire them for disobedience.
But everyone is subject to the same laws (basically, there are temporary and time limited exceptions for members of Congress and the President), so if a police officer commits a crime he could be arrested, tried and convicted.
But....the courts (see castle rock and warren vs District of Columbia) have ruled that the police do not have a positive duty to perform their job.
Which makes sense. Take the simple example of a hostage situation, if they have a positive duty to do something, then any time spent trying to negotiate a peaceful ending would be considered criminal. Police have discretion as to when and how to enforce the law, and it is their managers and supervisors (and to a lesser extent the people) who determine if they are doing an adequate job, not the courts.
So, depending upon the exact type of law enforcement officer they are, they may legally be able to tell both the President and the mayor to go away and stop bothering them.
Municipalities are creations of the states. Depending on the state, municipalities may have different levels of independence (and in some states, different municipalities may have different levels of independence within a single state, depending on the municipal charter). Well, except for Washington, DC, where I believe that the city mostly reports to Congress - but that's a onesie special case
States are considered sovereign entities to some extent. Yes, Congress can pass laws that override state laws, but the concept of state sovereignty dates back to the founding of the country (though it was paired back a bit when the Articles of Confederation were supplanted by the constitution. An example of this is how the President has absolute pardon power for federal convictions and zero pardon power for state crimes.
The President has absolutely no constitutional powers over cities. That said, many/most of the programs that Congress passes and funds leaves it to the executive branch to administer. What the President can say he/she's going to do is withhold Congress-passed funds from a city if it doesn't follow his/her dictates.
The Trump administration has tried this with some California cities. I believe that so far, the cities are winning the ensuing court cases.
It's also worth noting that in some US municipalities, the city will have a weak mayor form of government (as opposed to having a strong mayor. Dallas is an example. The police in Dallas report not to the mayor, but to the city council as a whole, through the city manager. Most executive responsibilities are invested in the city manager and not the mayor.