One of the best answers to the Independent voters who say "I vote for the person, not the party" is Mike Rosen's column, republished every two to four years entitled "Why Party Trumps Person."
Here it is, to give you a few ideas for discussing this issue with less educated voters.
"Why Party Trumps Person" by Mike Rosen, from 2004
With just 80 days to go before the election, it's time for my quadrennial column on party vs. person. I've been offering and updating this polemic for more than 20 years. For veteran voters, this may be review; for rookies, perhaps, a new concept.
A time-honored cliche heard every election year goes something like this: "I'm an independent thinker; I vote the person, not the party." This pronouncement is supposed to demonstrate open-mindedness and political sophistication on the part of the pronouncer. It's your vote, cast it any way you like - or not at all. But idealism and naivete about the way our electoral process and system of government works shouldn't be mistaken for wisdom or savvy.
For better or worse, we have a two-party system. And party trumps person. Either a Republican, George W. Bush, or a Democrat, John Kerry, is going to be elected president in November. No one else has a chance. Not Ralph Nader, not the Libertarian candidate, nor the Communist, nor the Green. Minor party candidates are sometimes spoilers - like Nader costing Gore the presidency in 2000 - but they don't win presidential elections. Ross Perot got 20 million popular votes in 1992, and exactly zero Electoral College votes.