I wish I could say this without being crass... but...
Protest marches are most effective when they appeal to the unemployed (who have the time to participate) and are targeted towards politicians who cater to the unemployed.
Think "Occupy Wallstreet"... The accountants, bankers, and lawyers in Manhattan did not organize their own "occupy" movement in response. The used the power of their wallet. In the end, the only thing the "occupy" movement succeeded in doing was putting a few unlucky restaurants out of business, spreading a lot of STDs, and smoking a lot of weed.
We, the gun-owners, tend to have full time jobs and disposable income. Well-written letters and campaign donations are our best weapon.