If you really want to signal your feelings on this to your congresscritter, don't write, don't email, and don't sign a petition. Call them. Speak with a human being in their office, and make sure that person understands that you're a voter, in his or her district, and that you're willing not only to vote, but to donate to or against a candidate and campaign on the basis of this issue.

Source: my cousin and his wife were both Senate staffers for several years.