Though there are rules that the state government can impose, the federal government can impose its power over the state that it can overrule the laws that the state government has, as long as, the federal government work within the powers stated in the Constitution.
Sixteenth Amendment:
"The Congress shall have power to lay and collect taxes on incomes, from whatever source derived, without apportionment among the several States, and without regard to any census or enumeration."
Nineteenth Amendment:
"The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of sex. Congress shall have power to enforce this article by appropriate legislation."
Twenty-sixth Amendment:
"The right of citizens of the United States, who are eighteen years of age or older, to vote shall not be denied or abridged by the United States or by any State on account of age. The Congress shall have the power to enforce this article by appropriate legislation"