Nonprofit and nonpartisan research may be useful in exploring the history of a given topic and providing supporting detail. Nonprofit research is important because it reduces the likelihood that researchers have a financial incentive to find a particular result or leave out details. Nonpartisan research is done by organizations which are committed to not favoring a political party. In the US, this usually means the organization is not affiliated with either the Democrat or Republican party.
Opinion polling can be useful for researchers in determining majority preferences, including by demographics such as geographical location, age, sex, etc. and additional factors, such as political affiliation. Be sure to check which organization is conducting the poll and what their goals are.
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