The miraculous rescue of Elizabeth Smart and the emerging details of how her captors hid the young Utah girl in plain sight for nine months have given powerful momentum to legislation that will create a national child kidnapping notification network. The president has long wanted this Amber Alert system. Congress overwhelmingly supports it. Implementation may be months away.

Not, as one might suppose, because of bureaucratic inertia, but because one key member of Congress insists that this widely popular proposal be tied to other proposals that, though directly related to the issue of child abduction, cloud the issue. Rep. James Sensenbrenner, Republican of Wisconsin, wants to include tougher penalties for child kidnappers along with the establishment of this enhanced recovery network; as chairman of the House Judiciary Committee, he has the clout to insist his views get a fair, and in this case, unnecessarily protracted, hearing.

Amber Alerts are named after Amber Hagerman, a 9-year-old Texas girl kidnapped in 1996. Like Elizabeth Smart, the aftermath of her case produced many reports from people who saw the girl in the company of her abductor but who were unaware of the ongoing search. Unlike Elizabeth Smart, the aftermath of her case was not a joyous homecoming but murder.

Since that time, Amber Alert systems have been established by some 85 communities across the nation: photographs and descriptions of the abducted child are sent immediately to all area news outlets, public-safety agencies, schools, hospitals and participating businesses; electronic highway signs make information about the victim and the assumed perpetrator known to all motorists. The Justice Department estimates that 34 children have been recovered safely through this local initiative. The national system would provide matching grants to states and communities for equipment and training, and would make available nationwide the considerable federal resources for investigation and information-sharing.

Rep. Sensenbrenner’s additional proposals have merit: deny pretrial release for child rapists and abductors; eliminate the statute of limitations on child abductions and sex crimes; allow judges to extend the supervised term of released sex offenders to life and require life sentences for twice-convicted sex offenders; double the money for the National Center for Missing and Exploited Children to $20 million a year through 2005 and mandate a 20-year sentence for a family member who kidnaps a child. They also present problems: the constitutional challenges they will certainly raise could delay the implementation of the entire package for years. In the near term, the differences between the stand-alone Amber Alert bill already passed by the Senate and the Sensenbrenner version endorsed by his committee and now headed for a House vote could result in a reconciliation delay of months.