Online analysis of American National Election Survey from Berkeley's Survey Data Analysis. This is a great place to start if you want to explore questions asked, get initial frequencies, or select individual questions across surveys for data download.
Supplementary Empirical Teaching Units in Political Science (SETUPS) are modules designed for use in teaching introductory courses in American government and politics. The modules are intended to demonstrate the process of examining evidence and reaching conclusions in a way that stimulates students to think independently and critically, with a deeper understanding of substantive content.
Datasets available here include his Federal Elections Project (census to precinct-level elections data), Candidate Quality and U.S. Senate Election Data,
Congressional District Demographic and Political Data, and the Southern Politics Project data.