I don't think not voting is irresponsible. I think voting only matters in certain states. If you are in California, sure, it's good if you vote Republican to show our numbers, and I hope there's enough of us out there to win, but I can see why you would find it pointless. Personally, I think voting is a good thing, but you are not selfish or irresponsible if you don't vote; it's a completely understandable choice.