I think you've hit upon one of the greatest weaknesses of our democratic system. One ends up voting for the candidate, if one does not feel so disenfranchised that one doesn't vote, who most closely matches our opinions and ideas, even if we only agree with that candidate 2% of the time.
Here are some of the other "greatest weaknesses" in our surprisingly non-democratic system of government, at least as I see them.
+ Partisan Gerrymandering that greatly benefits the ruling party (and punishes minority parties) every ten years.
+ Lack of Transparency. Even to this day there is no way to verify that your vote was counted or who it was counted for. We get all of the detriments of new technology (no paper records, no recounts) with none of the benefits (anonymous verification of your own vote).
+ An Electoral Collage that makes a blue vote count for nothing in a red state, a red vote count for nothing in a blue state, and a third party vote count for NOBODY AT ALL.
+ Virtually Unlimited Private Funding of elections that helps create a universal conflict-of-interest that can be spread across every single politician and party. Large companies can simply fund both sides of the isle. That way no matter who wins they ALL owe something in return. And if they ever don't live up to that assumption you can simply fund the challenger the next time around.
And that's just a few obvious issues right off the top of my head.
Being the "best that's ever been" is small comfort when you live in a system this fundamentally flawed, this easily corruptible, and this difficult to fix.