Aly & AJ's visit to the White House arrives just over a week after four people were killed and seven students were injured by a school shooter with an AR-15 type gun in Georgia.

It's taxing every night, but Aly and I feel we have a duty there, and I don't think we're going to stop anytime soon," says AJ Michalka, 33. "The work we're doing, it matters. It's important." ...