Why do political votes seem to frequently be evenly split?

So a few years ago I started noticing that elections often seemed to be closer than I would have expected. Each major party could potentially win. And I wondered how it seems to happen in the the US and Israel and elsewhere. And I realized what I assume many people already knew – but no one ever said..

Simply stated, assuming liberals vs. conservatives for example, there are forces that push the left further left and conversely the right gets pushed further right – each to differentiate and attract people on their side of the aisle.

But in a two major party system – or a right vs. left scenario – you need to capture enough of the center to get to say 51% without pushing to far to the other side that you will anger your natural voters. So the battle ends up being how to be squarely in your own camp and also have policies and plans that will attract the middle – if both parties do it right they should overlap in the center – which leads to a close election.

I think this is obvious once you think about it – but in case it’s not…