Those are definitely bad amendments but I wouldn’t call them “fatal.” We’re suffering death from a thousand cuts. But you’re right, viz. just because an American is breathing should not give them the right to vote.
Increasing prosperity guaranteed that that unitary government would become by degrees totalitarian.
Giving women the vote changed the nature of the electorate fatally. My wife convinced me of this one. Women will tend to vote for security and as marriage breaks down that gets intense. They vote for a husband. Liberty is much less important to women in the aggregate.
Three amendments, the 16th, 17th, and 19, were the Wilsonian Progressive Amendments. They have got what he wanted. It just took a century.