If you combine results from multiple polls taken at the same time, you can think of it as one huge poll. (businessinsider.com)
UPDATE: Thanks to Lawrence Hamilton for posting a link to their analysis of multiple polls on this and related issues in PLOS ONE. (rabett.blogspot.ru)
Now that multiple polls show her losing, she's turned to one of the most partisan figures in the nation, Democrat Hillary Clinton, to carry on Kloppenberg's personal attacks,» said campaign spokesman Luke Martz. (host.madison.com)