The survey suggests online video is not an ideal way for political candidates to reach voters. However, that 35 percent figure represents millions of people.

Video produced by the campaigns appears to be the least attractive to potential viewers. While 27 percent of those who have watched online video say they have watched a news story about a campaign or candidate, only 14 percent have watched a candidate interview; 14 percent a political speech; 11 percent a political advertisement; and 10 percent a campaign video.

The Harris Poll surveyed 2,455 U.S. adults with Internet access. The poll found 1,983, or 81 percent, had watched video.

Democrats were more likely than Republicans to watch political videos, and were also more likely to use them to decide whom to support. Republicans were more likely to watch video of candidates they know they do not support.