Although I agree with your premise and nearly all of your arguments concerning the inherent weaknesses of liberals challenging an autocratic threat to democracy, I cannot accept your argument that the electoral college was created to support slave states.
The three-fifths clause was inserted to mollify slave states, but not the electoral college. The electoral college was created both to limit the influence of large states and to distance the election of the president from direct popular vote. Of the thirteen states at the time of the writing of the Constitution, the three smallest were Rhode Island, in New England, Delaware, a Middle state with a free black majority, and Georgia, in the South.
The largest state, the state many feared would dominate the new republic, was Virginia — also the largest slave-holding state. Furthermore, the Articles government had passed the Northwest Ordinances which provided a means for new states to enter the union and banned slavery in the area north of the Ohio River. The framers of the Constitution almost certainly foresaw these new states as small states, as well.