Here's something I put into an email to a friend - I think it's worth remembering.

"America is great, because we can, every 4 years, have a revolution. 100% of the Executive, 33% of the Senate & 100% of the House is able to be replaced through the will of the people. It is our duty as activists to make sure that they have an opportunity to make that choice. Only the voters en masse can turn the course of this country, and they can only do that with the choices that we give them."