Health Poll Database. Search 85 years of US Health Polling Data. Curated by the Roper Center at Cornell https://www.healthpolldatabase.org/hpd/
Kaiser Health Poll Data. Compiles data from many polling sources about topical health policy issues: http://kff.org/tag/tracking-poll/
Roper Center. A broad archive of polling data on many topics: https://ropercenter.cornell.edu/