First, download the following app from sourceforge to make sure it works for you.
Then what you need to do is make a playlist and title it appropriately, such as Drug Policy - Decriminalize, then add suitable videos to it. Once you're done, you browse to the URL that holds your playlist and open of Youtube Extractor. Paste the url into the field and export it as a text file. Then upload the text file to the Youtube Captions folder. The file you want will take on the name of the playlist.
Try to choose videos that only show one perspective or has only one person speaking primarily. Just like the blogs, for the purposes of training the model we need seperate labels which means no cross over if possible. As for the captions themsevles, when you turn them on, an overlay will display that says "English (auto generated). Try to avoid these if possible, but if you think you have a really good video, put these in a seperate play list (no need to seperate by sentiment, as someone will have to go through them manually anyways).