I think you’re catching on.
That’s how you tell folks stayed home in 2012.
You look at the data from 2004 and when you notice there were 2 Million more (R) votes than there were in 2012, you conclude that some folks stayed home.
Now, we can do some more homework and look at Registered (R)s voting in 2004, 2008, and 2012, and that will paint a clearer picture.
Oh; I did this LONG ago!
Folks want to complain that Pubs stayed home and didn't vote for Romney over Obama; when this is patently FALSE.
Obama only ran twice; so it's no fair going back to Teddy Roosevelt and pulling up some numbers.