I agree there can exist a tyranny of the slight majority. But we’re talking about the EC, which is used to choose the President. Given the enormous power of the executive branch (relative to most parliamentary democracies, for example), this actually causes a minority to gain positive power over the majority. Positive power here meaning power to direct action through executive orders and (most importantly) military action, not merely to veto law. But the executive also enjoys some veto power!

The EC and 2 senators per state system that the US uses seems to lead to a tyranny of the minority, especially if you consider that senate “rules” regarding filibustering, simple, absolute majorities are almost all conventions rather than laws or immutable procedures.

However, I do agree with your line of argument as it relates to constitutional amendments.

Edit: I said the executive could create law, when I meant to say they can direct action.