It's kinda embarrassing how difficult the US makes voting for it's citizens. I can't think of any other democratic country that does it worse.
The problem is the generalizations. The "US" doesn't do voting at all. There's no such thing as a US election. What happens is 3142 county elections take place among all the states and D.C., each with its own rules and people running their local show. That's 3142 different voting authorities reporting up through a minimum of 51 state governments plus various other places like Guam, PR, and others that hold elections, just not for federal offices.
I've noticed a lot of people seem to not understand that the US is a lot like the EU in terms of just how much autonomy each individual state has, separate from the overall governing body. The US has more cohesion than the EU, but there's still a very clear separation between states in the same way that nations within the EU are clearly separate as well.
I'm fully aware of the Byzantine and totally unnecessary set of rules that have been implemented around voting - and have the temerity to argue that it's still stupid. Elections should be standardized and held in the same manner across the country. The current system is an embarrassment - and results are worse than basically every other democratic country I can think of.
AMENDMENT X [1791]
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.
The Framers dreaded concentrations of power so they designed a government consisting of a sovereign national government (federal government) and sovereign State governments.
Under the Supremacy Clause all States must comply with federal law but under the 10th Amendment each State has sovereignty over all other matters including the rules and administration of elections.
Each State's political subdivisions also have power to establish election procedures and how they are administrated.
My favorite explication of federalism is Justice Hugo Black's reverential embrace of it in
Younger.
Younger v. Harris (1971)
This underlying reason for restraining courts of equity from interfering with criminal prosecutions is reinforced by an even more vital consideration, the notion of "comity," that is, a proper respect for state functions, a recognition of the fact that the entire country is made up of a Union of separate state governments, and a continuance of the belief that the National Government will fare best if the States and their institutions are left free to perform their separate functions in their separate ways.
This, perhaps for lack of a better and clearer way to describe it, is referred to by many as "Our Federalism," and one familiar with the profound debates that ushered our Federal Constitution into existence is bound to respect those who remain loyal to the ideals and dreams of "Our Federalism."
The concept does not mean blind deference to "States' Rights" any more than it means centralization of control over every important issue in our National Government and its courts.
The Framers rejected both these courses.
What the concept does represent is a system in which there is sensitivity to the legitimate interests of both State and National Governments, and in which the National Government, anxious though it may be to vindicate and protect federal rights and federal interests, always endeavors to do so in ways that will not unduly interfere with the legitimate activities of the States.
It should never be forgotten that this slogan, "Our Federalism," born in the early struggling days of our Union of States, occupies a highly important place in our Nation's history and its future.