Briefing Room: Colorado school shooting, FBI investigating domestic terror cases, 2020 elections

The latest politics headlines form Washington, DC. SUBSCRIBE to ABC NEWS: https://www.youtube.com/ABCNews/ Watch More on http://abcnews.go.com/ LIKE ABC News on FACEBOOK https://www.facebook.com/abcnews FOLLOW ABC News on TWITTER: https://twitter.com/abc GOOD MORNING AMERICA'S HOMEPAGE: https://www.goodmorningamerica.com/