majority (8 questions tagged; 877 questions using the term)
supermajority (2 questions tagged; 26 questions using the term)
Both terms seem too general to be of value as tags. They may apply to elections and referenda, passage of legislation, composition of a legislature, demographics, etc., even "age of majority" and, in some cases, "majority" is the margin of the winner in an plurality election.
Whatever "majority" may be about is dependent on its context in the question. The same applies to "supermajority".
One question: How true is it that people vote for parties/people that benefit their stances most? Then does majority rule offer "best outcomes"?, uses majority as its only tag, but the question appears to be about, and may be sufficiently tagged as, democracy and political-theory.