4.86% Swing in 2012

[bgwah]

^ That would be a full swing. You said it was a half-swing initially.

A half-swing to the Republicans would be: 9.72/2=4.86. Subtract 4.86 from the D margin in 2008 (7.26-4.86=2.40).

So a "half" swing back to the Republicans would result in a D +2.40 election.

Does slicing off 4.86 from Obama and adding 4.86 to McCain result in this margin? No,  it results in R + 2.45. Which is  the 2004 margin, meaning it's just a full reverse swing.

I think that's the source of confusion, at least. I don't know really know what you were trying to do.

[bgwah]

Here is a tie election, with each candidate getting 49.24% (indie/third party total remained the same):

272-266 Obama. Does the EC favor the Democrats now?