Does the US federal government have the power to introduce any restrictions relating to the coronavirus, be it anything from a mask mandate to a full lockdown? Or does the Tenth Amendment mean that it is the exclusive responsibility of the several states to do so?
The answer will depend on how the federal government intends to introduce any restrictions more than what kind of restrictions they put in place. What is possible will change if they try to make rules and policies directly of if they try to use funding or other measures to get the states to follow the polices they want them to.
While not directly related you could look at the issue of the rules to require someone to be 21 in order to drink alcohol. This is something that is controlled at the state level but is set because of a mandate at the federal level. The way they managed to do this was to remove funding for anyone who didn't follow the new minimum age rules. It is possible that they could do a similar tactic for any covid-19 restrictions that they have trouble getting into place.
In 1984, the National Minimum Drinking Age Act passed, which stated federal highway funds would be withheld from U.S. states that failed to set the minimum legal drinking age back at 21. By 1988, all the states had adopted the age minimum.
What powers, if any, does the US federal government have to introduce coronavirus restrictions?
The federal government's power is limited to isolation and quarantine and support for state quarantines.
The Federal government derives its authority for isolation and quarantine from the Commerce Clause of the U.S. Constitution. Under section 361 of the Public Health Service Act (42 U.S. Code § 264), the U.S. Secretary of Health and Human Services is authorized to take measures to prevent the entry and spread of communicable diseases from foreign countries into the United States and between states.
The authority for carrying out these functions on a daily basis has been delegated to the Centers for Disease Control and Prevention (CDC).
Under 42 Code of Federal Regulations parts 70 and 71, CDC is authorized to detain, medically examine, and release persons arriving into the and traveling between states who are suspected of carrying these communicable diseases. As part of its federal authority, CDC routinely monitors persons arriving at land border crossings and passengers and crew arriving at U.S. ports of entry for signs or symptoms of communicable diseases.
When alerted about an ill passenger or crew member by the pilot of a plane or captain of a ship, CDC may detain passengers and crew as necessary to investigate whether the cause of the illness on board is a communicable disease.
The federal government may call upon federal law enforcement and the military to enforce isolation and quarantine, either state or federal.
State and local Quarantines. State and local officials draw their authority to enforce State and local quarantines from State and local law. Under section 311 of the PHSA, 42 U.S.C. § 243(a), the Secretary of Health and Human Services is authorized to accept State and local authorities’ assistance in the enforcement of Federal quarantine rules and regulations, and is required to assist State and local authorities in the enforcement of their quarantines and other health regulations.
The U.S. Coast Guard, and “military officers commanding in any fort or station upon the seacoast,” as well as Customs officers, which may include Customs and Border Protection officers and Immigration and Customs Enforcement special agents, must, at the direction of the Secretary of Health and Human Services, aid in the execution of such State quarantines and other health laws “according to their respective powers and within their respective precincts” (42 U.S.C. § 97).
The President also could use the Insurrection Act (see above) and use the Armed Forces or federalized National Guard to help suppress violence arising out of a State quarantine, as for any other law enforcement activity permitted under the Insurrection Act, 10 U.S.C. §§ 251-2552, provided the requirements for using the Act described above are met (e.g., if the President is asked by a State to assist and if the defiance to the State quarantine orders amounts to an insurrection against State authority that the State cannot handle (see 10 U.S.C. § 251)2, or there is widespread unlawful activity that has the effect of depriving people of rights secured by the Constitution and laws) (see 10 U.S.C. § 253)2.
Federal Quarantines. Customs officers, which may include Customs and Border Protection officers and Immigration and Customs Enforcement special agents, and the U.S. Coast Guard have specific authority and responsibility to assist with the enforcement of quarantines at ports of entry (42 U.S.C. § 268). With regard to other Federal law enforcement officers, the United States Marshals Service as the broadest of Federal law enforcement missions, 28 U.S.C. § 5641 along with other Department of Justice agencies (FBI, DEA, ATF) can be directed by the Attorney General to enforce quarantines. The U.S. Marshals Service can also deputize other Federal law enforcement officers throughout the executive branch to give them law enforcement powers in circumstances that extend beyond those for which they are otherwise statutorily authorized to exercise them, as was done during Hurricane Katrina.
Under the Insurrection Act the President may direct the military to enforce quarantines, or conduct security functions such as guarding stockpiles and pharmaceuticals, when he finds it necessary to enforce Federal law (see 10 U.S.C. §§ 252-2542), or other prerequisites for use of the Act described above are met.
1Changed from 28 U.S.C. § 565, probably a typographical error.
2Changed from original due to renumbering.
Does the US federal government have the power to introduce any restrictions relating to the coronavirus, be it anything from a mask mandate to a full lockdown?
No, at least not for the general public. Some restrictions may be implemented for federal employees, the active duty military, and visitors to government buildings. Thus, restrictions on the general public are at the discretion of state and local governments.
The basis for federal law is the "Commerce clause"3. Arguably, an individual not wearing a mask (or refusing vaccination, or otherwise ignoring recommendations of the federal government) is not participating in interstate commerce.
However, some argue that certain regulations implemented in 42 CFR Part 70 - INTERSTATE QUARANTINE do allow the CDC to to introduce broad restrictions on individuals.
42 CFR § 70.2 - Measures in the event of inadequate local control.
Whenever the Director of the Centers for Disease Control and Prevention determines that the measures taken by health authorities of any State or possession (including political subdivisions thereof) are insufficient to prevent the spread of any of the communicable diseases from such State or possession to any other State or possession, he/she may take such measures to prevent such spread of the diseases as he/she deems reasonably necessary, including inspection, fumigation, disinfection, sanitation, pest extermination, and destruction of animals or articles believed to be sources of infection.
42 CFR § 70.6 - Apprehension and detention of persons with quarantinable communicable diseases.
(a) The Director may authorize the apprehension, medical examination, quarantine, isolation, or conditional release of any individual for the purpose of preventing the introduction, transmission, and spread of quarantinable communicable diseases, as specified by Executive Order, based upon a finding that:
(2) The individual is reasonably believed to be infected with a quarantinable communicable disease in a qualifying stage and constitutes a probable source of infection to other individuals who may be moving from a State into another State.
That the Director of the Centers for Disease Control and Prevention "may take such measures to prevent such spread of the diseases as he/she deems reasonably necessary" appears to permit such actions; however, the regulation appears intended only to identify and remove "sources of infection" to prevent transmission to other states.
It is clear that any individual "reasonably believed to be infected" may be quarantined, again relating to interstate travel.
Note that the "Executive Order" in 42 CFR § 70.6 (a) applies to quarantines.
In 42 CFR § 70.14 - Requirements relating to the issuance of a Federal order for quarantine, isolation4, or conditional release, it is a bit of a stretch to take the position that the entire population of a state, or all states, could be subjected to Federal order for a mask mandate or lockdown (related to isolation).
3Article I, Section 8, Clause 3 — To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes;
4Isolation means the separation of an individual or group reasonably believed to be infected with a quarantinable communicable disease from those who are healthy to prevent the spread of the quarantinable communicable disease.
Or does the Tenth Amendment mean that it is the exclusive responsibility of the several states to do so?
The Tenth Amendment is not relevant. If members of Congress can find authority in one of the enumerated powers, they can write a law to impose any "necessary and proper"5 restriction.
The Tenth Amendment’s simple language — “The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people” — emphasizes that the inclusion of a bill of rights does not change the fundamental character of the national government. It remains a government of limited and enumerated powers, so that the first question involving an exercise of federal power is not whether it violates someone’s rights, but whether it exceeds the national government’s enumerated powers.
In this sense, the Tenth Amendment is “but a truism.” United States v. Darby (1941). No law that would have been constitutional before the Tenth Amendment was ratified becomes unconstitutional simply because the Tenth Amendment exists. The only question posed by the Tenth Amendment is whether a claimed federal power was actually delegated to the national government by the Constitution, and that question is answered by studying the enumerated powers, not by studying the Tenth Amendment. That was the understanding of the Supreme Court for nearly two centuries.
5Article I, Section 8, Clause 18 — To make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof.
The federal government has a well established history of claiming that emergencies allow them to control the people, such as putting people in prison for criticizing the country's involvement in a war, interning people based on their ancestry, conscripting them, etc. The current administration has not been shy about broadly interpreting federal powers, sending federal employees to grab people off the street to "protect national monuments", charging people under federal arson laws because a business that bought cups from out of state was harmed, etc. It would not be difficult to come up with an argument for mask mandates or lockdowns. If a state has an excessive amount of COVID cases, people won't want to visit, which affects interstate commerce, so federal jurisdiction. Ultimately, it comes down to what how broadly the courts interpret the commerce clause and other federal powers. If they're willing to agree that someone growing wheat on their own land and not selling it is under federal jurisdiction, then surely someone spreading germs is, especially if some of the people they're spreading germs to might be traveling between states.