Twitter is unique in that you don't have to identify who you are. That's really important in a lot of democracies around the world, where it's important to have an open communication platform.
When it comes to debates and how we track our data, it's also important to understand how those measurements play out. You may respond to something with a hashtag and I may just say the political party, but we're both talking about the same event in the same time period, so we're able to take that aggregate number of key words and look at when people are responding and make conclusions about what moment they are responding to.
Often those are the opportunities to persuade somebody, and campaigns and parties are often on Twitter during debate too, finding those persuadable people who are tuning in to learn more.