This page will help you locate good-quality information to support speeches or pro/con presentations on controversial topics.
A great starting point, with lengthy, objective overviews of major issues.
The Congressional Research Service prepares excellent reports for the U.S. Congress that analyze issues under consideration. Find them here:
Limit your searches to Scholarly Journals if scholarly sources are required.
Great for finding up-to-date news on your issue, plus case studies or examples that can illustrate your points.