One significant aspect of US laws, and especially cannabis laws, is states rights. Even if something like HR 5843 (
info here, please contact your representatives) passes, it will only move the issue to the individual states.
The issue is somewhat complicated: Places like California and Alaska who have lenient policies use states rights to support cannabis use, but have to worry about the potential to be overridden by federal laws. On the other end of the spectrum, places like Alabama will use states rights prevent cannabis use (AL has 3 or so years minimum mandatory sentencing for possession and an overloaded prison system and a deficit budget as a result) even if it becomes federally legal.
I'll avoid going into a long rant -- My point, however, is that there is a lot *to* be done, and a lot that *can* be done, both locally and on the national level. Anything that contributes to awareness of the realities of cannabis use, especially the medical benefits, is great.
For US citizens, follow NORML's news postings about legislative actions in your state and national bills such as HR5842 and HR5843. Contact your representatives and let them know you vote based on this issue, if you can risk it. It does help and that, when it comes down to it, is how legislative changes happen.