CQ Researcher Go Here First.
Has a section devoted to Pro / Con opinions.
Editorials or Commentaries
Often you can find Pro/Con opinions in editorials and commentaries. One place to for these is Academic Search Complete.
Do a keyword word search with the word "editorial" and your topic in order to find possible Pro/Con items.
ex: gay marriage AND editorial
Helpful search terms include: support, proponents, benefit, good
ex: gay marriage AND proponents , gay marriage AND benefits
Helpful search terms include: opposition, opponents, skepticism, harm, bad
ex: gay marriage AND opponents, gay marriage AND harm
Other keywords that might be useful are: analysis, opinion, commentary, public opinion, evaluation, viewpoint, debate, controversy, and skepticism.
Good for finding topics and providing background information.