The tags public-opinion (56 questions; no tag wiki) and polling (183 questions; "A sampling or collection of opinions on a subject, taken from either a selected or a random group of persons") seem fairly similar. There's a decent overlap between the two tags, and most questions only tagged with public-opinon seem to be either explicitly looking for polling data, or can be best answered through the use of said data - for example:
- Was the impeachment of Donald Trump supported or opposed by the general public outside the United States?
- Do Polish citizens support law that allows judges to be disciplined for criticizing the system?
- Is the French public opinion more favorable to Muslims than to Jews?
- How high is sympathy for Israel among Bolsonaro's supporters and/or Brazilian Evangelicals?
- If climate change impact can be observed in nature, has that had any effect on rural, i.e. farming community, perception of the scientific consensus?
- Public opinion: Jeremy Corbyn for Prime Minister
- Are there polls on US public support for a wealth tax?
On the other hand, there are some questions where a synonym wouldn't really make sense, for example:
- Why do some incidents become cause célèbre?
- Does the year 2000 observation that issue alignment mainly affected the US political parties, but not the public at large still hold?