Is it feasible to boycott a state?

I just noticed that a website I frequently order from is based in Arizona (at least that is where their printing press is located). I, along with many others, are opposed and upset with the recent immigration legislation passed in Arizona. I’m thinking that an economic boycott might be on order. Can a state really be boycotted? Does it even matter given our global economy? How much “boycotting” would be required for there to be an impact on the state? Would sending a letter to the company outlining my decision be as useful as simply buying from a competitor?