FDsys (Single most comprehensive source for official publications from all three branches of the US government, as well as independent agencies. This resource provides access to a broad array of full-text databases and finding aids)
PewResearch Center (Contains surveys and reports produced by Pew Research from 1987-present)
Gallop Poll (Contains recent polling data from the Gallup Poll)
New York Times Polls (Contains polling data collected by The New York Times from 2002-present)
Washington Post Polls (Contains polling data from The Washington Post from 1997-present)