Most of the slap on the wrist problem comes from judges who are unwilling to execute punishments that fit the crime. The only way around this is to enact minimum mandatory sentencing laws associated with the particular offense. Minimum mandatory sentencing laws essentially bind the judge to pass down certain punishments upon a plea of guilt or conviction of a certain criminal offense. Short of these, judges typically have a significant margin of discretion when it comes to sentencing.
To answer your question about bringing change. Everything of this nature happens on the legislative level. It has to be tabled and sponsored by a member of the legislative branch, after it has to survive a legislative committee and get the nod of both legislative branches where it may finally be signed into law.
Realistically, you would need to either have the ear of a state senator or representative by having several voices to push your cause. Typically these will be from grassroots movements. The down side, if it is not politically expedient for someone to grab onto, it may take many years before it is ever given serious consideration. Also, in times such as these with the economy, unemployment, and the related budget issues, poaching will not even be a blip on the radar 'to do list.' On the other hand, if you do nothing, then nothing will change either.
The single most effective thing you can do in terms of bang for your buck is simply write your senator and representative and tell them your thoughts.