The Constitution leaves the process of selecting electors to each state. Various amendments prohibit the states from denying the vote on the basis of race, sex, age, or the ability to pay a poll tax. There is no individual constitutional right to vote.
That being said, I think there would be tremendous benefit to enacting a test as a prerequisite to voting. Something along the lines of a watered down citizenship test.
Presidential elections have been reduced to the lowest common denominator. Campaigns are negative and full of lies. Why? Because those tactics work on people who are willfully ignorant of government. People who shirk their important responsibility to be part of an engaged and informed citizenry, which is absolutely necessary in a constitutional republic. These people should not be permitted have a say in the selection of representatives that will serve all the citizens. This is in everyone’s best interest.
I’m not talking about a lofty standard or a scheme to eliminate the vote of minorities or the poor. I’m talking “what are the three branches of the federal government?,” “how many senators does each state have,” etc.
In my opinion the accountability of representatives and dissatisfaction with politics in general will continue to accelerate in this country without something like this happening. Unfortunately it’s about as unpopular an idea as banning cats.