Immigration control _doesn't and won't_ help American workers. As long as push & pull factors exist, workers will come and get exploited. The only question is _on what terms_ they will get exploited -- as isolated illegal aliens with few rights, government-sanctioned "guest workers," or workers plain and simple on equal terms with "citizen workers."
That said, capitalism does pit workers against workers, and things look like a zero-sum game for job competition from the point of view of workers who see no alternative to capitalism (whether you are talking about import or immigration). The day American workers fully accept illegal aliens as brothers and sisters in solidarity is most likely the day when they become communist, and we are obviously not there yet. So how do we go from here to there? We can and should argue & struggle against xenophobia, but that doesn't solve the problem, does it? For xenophobia is mainly a symptom, not the cause.
Chuck0's idea (and the Seattle practice) of network is just fine if the only purpose of the protest is to say a symbolic No to the WTO. But in the absence of solid organization of those who think like you and I, it is no wonder that we (fragmented & disorganized, only loosely cyber-networked) become merely foot soldiers for loyal oppositions like Max and Hoffa, despite our intentions, no? (Max here is gracious enough to thank the Eugene anarchists for "just the right amount of windows broken" to make the point -- his point. Does this not make you think?) So, what is to be done?
Also, do you think that open borders arguments should be applied in all instances? Most migration in the world occurs not from poor nations to the rich core but among poor nations, I believe. Circumstances there are much more complicated than fighting xenophobia in America, Japan, or Australia (the latter is no-brainer for those who think like you and I). What do you think?
Yoshie