When I was a fresh voter in my first American election, I voted mostly for one party, and my parents at least half for the other. My parents were up-to-date on the contestants, their views, and their personalities. They often voted for the party they didn't belong to, if they felt that the people and issues involved warrented it.
I was a young leftist, and almost always voted democratic. And I would quiz my parents whom they were voting for. I don't know if they realized it at the time, but their answers were important to me. Even if I didn't agree with them, their opinions were noted with consideration.
I don't know if the same holds true for my sons. I asked my 2 youngest voters who they were chosing, and I receieved answers that surprised me. They pointed out certain concerns, and why they choose something that I would not suspect them of choosing.
I would not try to convince them other wise...because I doubt that arguing politics works, and it just causes fights. But I am glad that their choices were something I could swallow rather easily.