I think I missed that thread.
I found the article from the thread, but not the thread itself:
http://www.americanthinker.com/2010/02/mccain_and_hayworth_tale_of_th.html
The most recent online scores from the American Conservative Union are from 2008. In that year, John McCain scored 63 and had a lifetime average of 81.43. (All scores reported here are on a scale of zero to 100, with 100 being perfectly conservative according to the scorer.) His lifetime average put him in 32nd place in the 2008 Senate, or in the top 32%.
J.D. Hayworth’s last full year in Congress was 2006. His 2006 ACU score was 96, his 2005 score was 100, and his lifetime average was 97.56. His lifetime average put him in 16th place in the 2006 House, or in the top 4%.