It's true that the politicians can ignore the marches themselves. As events the marches are more useful in attracting people to your cause by showing that a large number of people believe something and if you believe it, too, then you can join a large group to support what you believe in.
The fruits of the Tea Party Patriot marches aren't the marches, the fruits are the melting of the phone banks, the increased daily activism and the votes in the ballot boxes by an increasingly large and "extremist mob." ;0)
So we need to calmly and politley tell at the beast to, please - oh please stop taxing us to death?????
The only thing that will stop the beast at this point is for us to stop feeding it. Starve the beast.