How do I find public opinion polls for a class or research?

The UCLA Data Archive maintains a collection of public opinion poll data, covering many years and countries. Some of these files come from the Roper Center. Some come from Inter-university Consortium for Political and Social Research (ICPSR). To see what is available on campus, click on this link:
https://www.library.ucla.edu/social-science-data-archive/about-data-archive

For more information about getting polls from the Roper Center, click: https://ropercenter.cornell.edu/

For more information about getting polls from the ICPSR, click: https://www.icpsr.umich.edu