Why not just broaden the scope of the racism tag? According to Wikipedia:
Racism is the belief that groups of humans possess different behavioral traits corresponding to inherited attributes and can be divided based on the superiority of one race over another. It may also mean prejudice, discrimination, or antagonism directed against other people because ...
You say you see a problem with the racism tag but how exactly would racial-discrimination be any different? It has all the same connotations as racism but is just saying it in a different manner. Personally I don't see a need for that tag or how it would apply to a question and the racism tag would not.
The discrimination excerpt includes racial discrimination.
Deliberately different treatment of people on the basis of characteristics regarded by others as irrelevant, such as gender, race, or sexual orientation.
The racism excerpt also includes racial discrimination.
Questions related to the prejudice, discrimination, or antagonism directed against ...
I am sure that there are a lot of interesting questions one could ask about Jersey. And I am also sure that there are a lot of interesting questions about Guernsey too. But so far nobody has asked any. So we don't need those tags (yet!).
The three questions mentioned here are neither specifically about Guernsey nor specifically about Jersey. They are all ...
As for the political-research excerpt, I suggest,
Political research is the branch of political science that investigates and analyzes activity connected to politics. Use this tag for questions about research into any aspect of politics. Consider [political-theory] if the question is not about research.
Responding to @JJJ's answer:
What is the difference ...
Without closely looking at the questions in that tag, I'd say it's a synonym of political-theory which has the following excerpt:
Political theory is the study of the concepts in politics. Use this tag for questions regarding political philosophy or scientific theories.
I think we should remove the political-research tag from those questions where ...
Is meek-single-transferable-vote so distinct as to need a tag separate from single-transferable-vote?
No, Meek's is one of a few commonly used STV systems. The others are Warren's and Wright's. These are all implementations of the Single Transferable Vote system.
I don't think it's necessary for these specific implementations to have their own tag.