In short [0], the idea of republicanism is that the people cannot be trusted to make political decisions; you need elder statesmen to do that. In other words, you need grown-ups. To this end, we have the electoral college, which is supposed to block any egregiously populist president. Well that is not how it worked out.
0. So short that it is misleading. I won't defend anything I say here, even though I believe it in principle.