The Presidential candidate debates : Sept. 26th ; Oct. 9th ; Oct. 19th
The Vice-Presidential candidate debate : Oct. 4th
Sept. 26th - enter this phrase, with quote marks: "HILLARY CLINTON AND DONALD TRUMP 2016 PRESIDENTIAL DEBATE" -- Result is the transcript of the 9/26 debate, from ABC News Special Report.
Oct. 4th - enter this phrase, with quote marks: "Senator Tim Kaine and Governor Mike Pence Participate in Vice Presidential Debate" - from CNN Special/Live Event
Oct. 9th - enter this phrase, with quote marks: "2016 LIVE TOWN HALL PRESIDENTIAL DEBATE" - from ABC News Special Report
Oct. 19th - enter this phrase, with quote marks: "Hillary Rodham Clinton and Donald Trump Participate in a Candidates Debate" - from CNN Special/Live Event
Factiva has a source type - Transcripts - you can select Broadcast - or a specific program such as 20/20 or 60 Minutes.
[choosing a source type is clunky; I have scrolled through hundreds of results and have noted above the specific "title" that is the full text of a debate]
Here's the long path to selecting a Transcript...
Click on "Source" from the left frame. From the box "All Sources" , click on the arrow and select "By Type", then scroll down to "Transcripts" and click on the plus sign ( + ) to select a transcript. For example, a CNN Special/Live Event - click on the blue triangle -- the code for this type of transcript (which is rst=cnnsp ) is now in the search box. You will have to enter "and" [without quote marks] as well as word(s) to search in order to get results.
Example: rst=cnnsp and clinton and trump and debate