If you're researching a controversial topic (or trying to decide on one to research), check out either CQ Researcher or Opposing viewpoints. Both databases focus on covering multiple sides of controversial issues.
Databases are the main place for finding articles through the Library. You may find commentary on fairly recent speeches through the general databases listed below. Both scholarly and popular pieces of commentary on speeches are contained in this database.
To find writing on historical speeches, try a history database: