Human beings are flawed. And human beings with the sorts of personalities that, in a democracy, push to the front shouting "Vote for me!", and who actually SUCCEED at it, are generally doubly so.
In a monarchy, such as that under which the ancients of the Bible, both testaments, lived, politics was not a province of the people at all. Nor was it during the Reformation: all government was hereditary monarchy then.
The age of revolution added a wrinkle that is not discussed in Scripture, because it didn't exist, and that is not much discussed in the theology of the Reformation either (because where it did spring up, democracy was associated with the Anabaptists, and they were violently crushed out by Lutheran and Anglican or Catholic princes wherever they arose - EVERY crowned head felt threatened by THAT).
But revolution did come, first to the Americans, then to the French, and from them, to all of Europe. The people took the crown off the king's head, broke the crown into a million pieces, and each took a piece for themselves. So now, thanks to this, we ALL are fractions of the king. Our ancestors had no political responsibility (unless they were nobles), but we have all of the political responsibility. It's not an easy burden, because people strive for every office, constantly, and offices in America have tremendous power within their sphere.
Usually the question is a matter of which sinner your own sinful self decides to vote for, and that's usually based on a tribal partisanship.
But most of us don't like to look at ourselves that way, so we claim (and really believe) that our choices are principled, not petty and partisan. And maybe that's even true. It almost doesn't make a difference. In virtually every election the choice is between a Democrat and a Republican, one one will win and add his own not-very-important vote and voice to a throng of politicians who haggle out the laws.
If we could draft people into office wwe would have very different governors. But we can't. Instead , we have to choose from the sort of men and women who thrust themselves forward clamoring for a vote and support. And they're usually quite imperfect, because they are headstrong, and generally more vain than is healthy.