1/4 vote Dem, 1/4 vote Rep, 1/4 aren't old enough to vote and 1/4 are apathetic. Sounds about right.
Regarding demographics, all the talk about how 'white' the Republican party is kind of fascinates me. According to the
2010 census 72.4% of the US population IS white ("white alone" to be specific). To be sure minority populations are growing rapidly, but they have a long way to go before any of them, or even all the groups together, become the majority in the US. If almost 3/4 of the US is white and if the Democratic party does a better job of appealing to minorities then it only makes sense that the GOP is made up of mostly white folks because there's nobody else left! It just doesn't seem like rocket science to get that far. How to appeal to those minorities and still maintain the base OTOH...