> Please cite me where the power to enact a requirement to wear masks is explicitly granted to the federal government.
Depends on the nature of the mandate. A simple hard mandate (everyone must wear masks in public or be subject individually to federal sanction) may not be authorized, but that's not the only shape of mask mandate possible.
A requirement that a state adopt and show adequate enforcement of control measures deemed necessary by the federal government, including (if deemed necessary) a mask mandate with given parameters or be subject to additional restrictions on interstate trade and travel to restrict the spread of disease to other states is absolutely not only within the scope of the Constitutional power of the federal government under the Commerce Clause, but also within statutory powers already granted to the executive branch under that Constitutional power, in the Public Health Services Act and elsewhere.
Depends on the nature of the mandate. A simple hard mandate (everyone must wear masks in public or be subject individually to federal sanction) may not be authorized, but that's not the only shape of mask mandate possible.
A requirement that a state adopt and show adequate enforcement of control measures deemed necessary by the federal government, including (if deemed necessary) a mask mandate with given parameters or be subject to additional restrictions on interstate trade and travel to restrict the spread of disease to other states is absolutely not only within the scope of the Constitutional power of the federal government under the Commerce Clause, but also within statutory powers already granted to the executive branch under that Constitutional power, in the Public Health Services Act and elsewhere.