On November 4, 2014, a small fraction of Americans will vote in the midterm election. Polls consistently show Republicans are very likely to win the Senate and make gains in the House. But why?

People tend to think of elections as one of two things: either it's the American people delivering a considered verdict on how the two parties are doing, or it's the two parties waging an epic battle using negative ads and ground games and messages and all the other dark arts of electioneering. In the first telling, the winner is whichever party has done a better job; in the second, it's whichever party ran savvier campaigns.

But there are other forces that decide elections. Each election has a basic shape that changes the campaigns the two parties run, the voters who show up to the polls, and ultimately, the winner. And the truth about the 2014 election is that the basic shape of this election favors the Republicans. But the basic shape of the next election won't. Watch the video to find out why.

And yes, we explain this using Donkey Kong levels.