The Tenth Amendment states "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."
If a State chooses to allow medical cannabis then the federal government should not take it upon themselves to reverse that law. If a state chooses to enact laws to prevent voter fraud then the federal government should not take it upon themselves to challenge that law.
The founding fathers wrote the Bill of Rights for a reason, and this administration is blatantly disregarding the Constitution and the Bill of Rights.