Economists love to talk about voting as a collective action problem, i.e., where the gain of an individual vote in terms of impact is far lower than the time and effort cost of the vote. They thus call voting paradoxical -- a characteristic that many pundits repeat.
But people vote, so there must be a reason.
I was chatting with a girl from Poland the other day about her country's current, semi fascistic but democratically elected government. She said "yeah, all the young people stayed home to protest the bad choices so that party won. Big mistake."
It occurs to me that parties exist to create an ingroup vs out group dynamic that will bind individuals together into teams. Thus voting becomes not an individual choice but group bonding exercise. I'm pretty sure that sociologists and political scientists get this but economists could do better.
Bottom line: Vote for your team, especially if it is gracious in victory.