From conservative economist John Cochrane, comes this:
“Democracy, and US democracy in particular, serves one great purpose—to guard against tyranny. That's what the US colonists were upset about, not the fine points of tariff treaties. US and UK Democracy, when paired with the complex web of checks and balances and rule of law protections and constitutions and so forth, has been pretty good at throwing the bums out before they get too big for their britches. At least it has done so better than any other system.”
But maybe not when every vote does not count: in the not-yet-reformed American system of choosing the president, the candidates do not need or bother to campaign for every vote, and under these circumstances a passionate minority of voters can keep someone in office even when the majority would rather have someone else.