Definition of bellwether states

[Antonio the Sixth]

That "voting for the winning candidate" criterion is utterly meaningless, especially in a close election (say the nation supports the Democrat by 1 point: is the state that went D by 50 points a better bellwhether than the state that went R by one point?). Bellwhethers should be defined by the similarity of their electoral results with the national results (similarity that can be defined in an easy binary way in two party systems as the difference between two margins).