Establish Boundaries
Political theory questions are often at-risk of being closed for being either too broad or opinion-based. To avoid this, it is sometimes helpful to establish some boundaries to the kinds of theories you are willing to entertain.
For example, this question might attract some close votes for being too broad:
Who should be able to make laws?
This question will likely attract close votes. Even though it's a basic political theory question, it will almost invariably attract opinion-based answers, rather than answers based on extant theory. Additionally, it is difficult to answer because it requires summarizing thousands of years of philosophy to adequately address.
Establishing clear boundaries can help both problems. One option is to specify a particular kind of theoretical lens to use:
In classical republican theory, who should be able to make laws?
Or reference a particular work:
In Utopia who is capable of making laws?
Or maybe a particular author:
According to Hegel, who should be able to make laws?
Although this example was based in moral theory, the same goes for questions of scientific theory. If you can narrow down the scope of your question your question is more likely to stay open, and you are more likely to get high-quality answers.
When You Don't Want Boundaries
Sometimes you really don't want boundaries. You might really want a broad survey of philosophic arguments across history, or perhaps you don't know enough about a subject to clearly say what kind of theory you are interested in.
We have had questions on broad philosophic themes, such as "What is the difference between a republic and a democracy?". These questions tend to attract answers based on personal opinion and low-quality sources (such as dictionaries). These questions are typically not a great fit for the StackExchange format and may be better asked elsewhere. Ask at your own peril.
If you don't know what theory is appropriate, saying so in your question is helpful:
What are the key theories regarding who should make laws? I'm sure that different theories have different recommendations, but I don't know enough about the subject to guess what theory I would be interested in.