Americans have been on a long, slow journey towards a powerful (tyrannical?) central government controlling every facet of life in America since Lincoln and the Civil War. Its been speeding up the past few decades.
They designated electors to each of the three political branches with the purpose of each institution in mind. As opposed to the House and Senate, whose members know their employers and thus whom they must satisfy, the Framers’ President was unbeholden to the people-at-large, states, Congress, faction, or collection of factions – what we know as political parties.