Fun fact: I just did a search on a news database. Roughly 15% of stories that mention Twitter also mention Trump, and roughly half of those seem to be about Trump's tweets.

I don't know if Trump is really causing Twitter usage to increase, but it has certainly made people who don't use Twitter more aware of it.

If you compare the awareness/user ratio on the various social media platforms, I bet Twitter's is pretty high, which means they have potential for significant growth if they can improve the UX and the "how do I use Twitter? Why would anyone use it?" problem.