Not really, but it's a question of how you want the data you are looking for to be displayed.
I was thinking in terms of a single map. It would look like a swing map, but it would be a strength map really - since it's not the same candidate. Does that clarify it?
If I overlay the Huckabee and Santorum strength maps, the Huckabee strength will be greater almost everywhere partially because Santorum ran against more candidates (Huckabee was 10% stronger statewide than Santorum - it's not an altogether even comparison.) Are you looking for a comparison of the strength of each candidate
against the statewide average?
Sorry if I'm being a little dense, but I just can't figure out in my own mind how to present the information you're looking for in a meaningful way