Amid the bad news this summer of racial tensions in Charlottesville and biblical-like floods in Houston and preening saber rattling between Pyongyang and Washington, a dangerous below-the-radar trend has been developing about which all who believe that the Constitution means what it says should be concerned. It is the reckless influence upon local law enforcement coming from the Trump administration.

Here is the back story.

In constitutional parlance, police power is the right and obligation of each state to legislate for the health, safety, welfare and morality of people in the state. This is what state and local governments do. And it is what the Constitution was written to prevent the federal government from doing.

When the states joined the union, they gave certain powers to the federal government, and they kept others to themselves.

The powers surrendered are articulated in the Constitution, and the 10th Amendment clarifies the truism that those powers not surrendered have been retained.

The traditional terminology for the powers retained is the "police power." The police power does not refer to police as in cops on the streets, but it does refer to states' powers to make laws and policies that are often enforced by cops on the streets.

In constitutional parlance, police power is the right and obligation of each state to legislate for the health, safety, welfare and morality of people in the state.

This is basically what state governments -- and local governments with the approval of their state governments -- do. And it is basically what the Constitution was written to prevent the federal government from doing.

Those who wrote, ratified and amended the Constitution all took pains to keep the police power out of the hands of the federal government for several reasons. One was federalism. The states are sovereign entities, 13 of which are older than the federal government. By retaining the police power in the states, the Constitution's drafters provided a check -- a limitation -- on the reach of the federal government.

A second reason for retention of the police power in the states is what President Ronald Reagan whimsically called voting with one's feet. He meant, of course, that since we all have the natural right to travel -- to leave a geographical area that has a government we reject -- we can go to a state more to our liking.

If you don't like the taxes in New Jersey, you can move to Pennsylvania. If you don't like the regulations in Massachusetts, you can move to New Hampshire. You can see the simplicity and constitutional beauty of his argument.

Yet the federal government -- notwithstanding which political party is in power -- has repeatedly found ways around these profound constitutional principles.

One way has been to use the commerce clause, which empowers Congress to regulate interstate commerce, to regulate anything that might affect interstate commerce -- from the wheat a farmer grows only for his family's own use to legal marijuana a pain-ridden patient grows only for her own use to countless items that never leave their state of origin or are not commercial in nature.

Another way for the federal government to reach into and control state and local behavior is by legalized bribery. For example, Congress cannot regulate highway speed limits or the minimum blood alcohol content sufficient to trigger DWI prosecutions, but it can offer the states cash to pave highways in return for the states imposing the congressional will on vehicle speeds and on DWI triggers.

And the courts have upheld this -- effectively telling the states that if they want the federal cash, they must accept the federal strings attached. Because the states are all cash-strapped -- and Congress knows that -- the states always take the cash and the strings.

Now back to the troubling trend this summer. The Department of Justice last month told local police in states that prohibit the seizure of a criminal defendant's assets before conviction that the police can just ignore these state prohibitions and follow the looser federal rule -- which does permit seizure of assets before trial, while the defendant is still innocent -- and the feds will share the seized assets with the local police who have seized them.

This is another example of federal bribery of state officials, although as yet untested in the courts.

This past week, the DOJ also announced it will be offering to local police vast amounts of surplus military equipment -- much of it new, fearful and lethal -- from body armor to listening devices to battle tanks.

If police begin to look like soldiers and carry soldiers' gear in soldiers' vehicles, will they begin to think like soldiers, whose goal is not to win hearts and minds and keep streets safe but to destroy the lives and property of the enemy in wartime?

Moreover, the strings attached to this federal hardware giveaway do not require congressional or even local government approval. They require only acceptance by the police and regular local use of the military equipment. Local police should not have this discretion and should not be subjected to this temptation.

Add to all this the recent DOJ threats to prosecute physicians and their patients who lawfully prescribe and use medicinal marijuana, President Donald Trump's personal advice to cops to hate and be rough with certain violent but untried suspects, and his pardoning of a former Arizona sheriff convicted of willfully disobeying a court order to stop arresting people on the basis of their skin color and we have a serious challenge to basic constitutional principles.

Those principles require adherence to the rule of law. And the rule of law mandates that police be local but subject to the Constitution and federal and state laws like everyone else. And it requires fidelity to the Constitution by those in whose hands the voters have reposed it for safekeeping.

The rule of law is the absolute condition for personal liberty in a free society. Without it, we will have the rule of tyrants.