morning, america. it's great to have cecilia vega in for george. you can't take his pen, even though it has his name on it. >> sorry, george. if it's not here, it says anchor extraordinaire. i might just sneak it away. here for all your presidential tweeting needs this morning. you let me know. >>> we're going to start with those teenage students calling for change after the school shooting, rallying all weekend. and now promising a march on washington for gun control. the president feeling the pressure. and our chief white house correspondent jon karl has the latest joining us from washington. good morning, jon. >> reporter: good morning, robin. the president had praised law enforcement for its response to the parkland shooting. but over the weekend, he unleashed a stunning new allegation, suggesting that the fbi failed to stop the shooter because it was too busy with the russia investigation. just days after he visited victims of the shooting, the president tweeted over the weekend...