Harvard Cooperative Election StudyA 50,000+ person national stratified sample survey administered by YouGov. The survey consists of two waves in election years. In the pre-election wave, respondents answer questions related to general political attitudes, various demographic factors, assessment of roll call voting choices, political information, and vote intentions. The pre-election wave is in the field from late September to late October. In the post-election wave, respondents answer questions related to the election that just occurred. The post-election wave is administered in November.