Proposition 1:  American "moderate" or "independent" voters are basically apolitical, and they vote because they feel it is their civic obligation, and not because they have any particular attachment to a political position.  They make judgments intuitively, responding positively to strong and straightforward statements of political position and negatively to verbose, carefully-crafted wonkery that "splits the difference" between two more extreme positions.

Example 1A:  Here are three positions on gay marriage:

1) Marriage is between a man and woman!

2) Blah blah blah equal respect blah blah blah special status of marriage in our society blah blah blah "civil union."

3) It's none of the government's business!  Let them get married!

The independent voter doesn't really want to think a lot about this issue, and will be attracted to positions 1 or 3, and will likely prefer either to 2.

Example 1B:  Here are three positions on health care:

1) Government can't do everything!

2) Blah blah many uninsured blah blah power of the market blah blah carefully considered this issue blah blah blah tax credits blah blah fully refundable.

3) Every other modern country has national health care!

Again, independent voters will be attracted to positions 1 or 3, and will likely prefer either to 2.