I think 40% of the Jewish vote always goes to the most electable socialist candidate.
1920 Harding (R) 43 Cox (D) 19 Debs (Socialist) 38
Well it was mostly Christians that elected Carter. Whatever.
Looks like 38 per cent in 1920, compared with 43 for the Republican. I think Debs was in prison at the time. Wilson had won in 1912 due to the Republican vote being split (Taft and TR), and Debs was perceived as having pulled votes away from Wilson. Soooo, Wilson had him imprisoned under the Sedition Act (if memory serves). Here's a nice photo gallery of Debs, including a 1920 campaign postcard:
http://www.eugenevdebs.com/pages/photo.html
http://www.eugenevdebs.com/media/EVDebs_president.jpg