This article places the attitudes of US unions toward immigrants within the
context of a "globalized" environment and a contested and problematic hist
ory of the US labor movement regarding its conflicting tendencies toward in
ternational solidarity and nationalism. Following a review of that history,
the article examines the relationships of four unions in the heavily immig
rant Miami, Florida area with immigrant workers in the past four decades. T
he evidence indicates that explanations for differing responses can be foun
d in the union's structure, its external environment, its leadership's visi
on and ideology, and its internal "cultural" practices.