He is partially right in that the Founders opposed the 12th. Amendment, and the EC is not a Democratic institution:
https://time.com/4558510/electoral-college-history-slavery/
"At the Philadelphia convention, the visionary Pennsylvanian James Wilson proposed direct national election of the president. But the savvy Virginian James Madison responded that such a system would prove unacceptable to the South: “The right of suffrage was much more diffusive [i.e., extensive] in the Northern than the Southern States; and the latter could have no influence in the election on the score of Negroes.” In other words, in a direct election system, the North would outnumber the South, whose many slaves (more than half a million in all) of course could not vote. But the Electoral College—a prototype of which Madison proposed in this same speech—instead let each southern state count its slaves, albeit with a two-fifths discount, in computing its share of the overall count.
Virginia emerged as the big winner—the California of the Founding era—with 12 out of a total of 91 electoral votes allocated by the Philadelphia Constitution, more than a quarter of the 46 needed to win an election in the first round. After the 1800 census, Wilson’s free state of Pennsylvania had 10% more free persons than Virginia, but got 20% fewer electoral votes. Perversely, the more slaves Virginia (or any other slave state) bought or bred, the more electoral votes it would receive. Were a slave state to free any blacks who then moved North, the state could actually lose electoral votes.
If the system’s pro-slavery tilt was not overwhelmingly obvious when the Constitution was ratified, it quickly became so. For 32 of the Constitution’s first 36 years, a white slaveholding Virginian occupied the presidency.
Southerner Thomas Jefferson, for example, won the election of 1800-01 against Northerner John Adams in a race where the slavery-skew of the electoral college was the decisive margin of victory: without the extra electoral college votes generated by slavery, the mostly southern states that supported Jefferson would not have sufficed to give him a majority. As pointed observers remarked at the time, Thomas Jefferson metaphorically rode into the executive mansion on the backs of slaves.
The 1796 contest between Adams and Jefferson had featured an even sharper division between northern states and southern states. Thus, at the time the Twelfth Amendment tinkered with the Electoral College system rather than tossing it, the system’s pro-slavery bias was hardly a secret. Indeed, in the floor debate over the amendment in late 1803, Massachusetts Congressman Samuel Thatcher complained that “The representation of slaves adds thirteen members to this House in the present Congress, and eighteen Electors of President and Vice President at the next election.” But Thatcher’s complaint went unredressed. Once again, the North caved to the South by refusing to insist on direct national election."