Hughes received one vote on the Independent ballot line.
Information on party affiliation of third-party candidates accessed via:
http://sos.iowa.gov/elections/pdf/results/60s/1964gencanv.pdf
http://www.ourcampaigns.com/RaceDetail.html?RaceID=174242
Source for Popular Vote data: Iowa Secretary of State. State of Iowa - Canvass of the Vote - General Election - November 3, 1964, Iowa Secretary of State (http://sos.iowa.gov/elections/pdf/results/60s/1964gencanv.pdf) (accessed 17 Aug 2012)