Congresspeople often seem to be addressed by celebrities (and sometimes teenagers who are foreign nationals). It's often unclear in what the person's qualification for commenting on legislative matters consists. How does one come to address congress (in a hearing, I guess)? Have these people submitted a request somewhere, or are they sought out by lawmakers?
They are invited. Based upon a number of factors:
But committees aren't going to call just anyone to the table; potential witnesses must be credible. Giving testimony is "an honor," says Michael O'Hanlon, of the Brookings Institution, but it's also "at some level, a validation" of the relevance of one's work. O'Hanlon, a national security and foreign policy expert who testifies before Congress about once or twice a year, says his organization's communications strategy includes efforts to keep him and his peers on Capitol Hill's radar through everything from invitations to events to a regular email roundup of published journal articles. "If nothing else, that helps them remember your name," O'Hanlon says.
The article then lays out some particular committee preferences for invitations: some prefer a stable of reliable groups or people, some prefer a balance of wonks and regular Joes, etc.
Note committees do get requests to testify. These are addressed to the Committee itself. And different avenues are available for differing types of testimony.
The Judiciary Committee, which holds hearings on topics ranging from voting rights to satellite TV, often gets far more requests to testify than it can accommodate. To give those who are not chosen to appear in person an opportunity to share their thoughts, the panel keeps the hearing record open for a week, allowing interested parties to submit written testimony. Sometimes, witnesses are federal officials: the attorney general, a representative of the Homeland Security Department. But, a committee aide says, other voices are often useful as well. And that's where Livier's testimony comes in.
Or they are subpoenaed.