It seems that McCain's solution to illegals upset some union workers mainly due to the fact that his 'solution' isn't a solution.
McCain's proposal is to give the illegals amnesty (despite his claims, it's still amnesty). The laughable highlight of his plan requires every illegal to pay a $2000 fine! On one hand you have the government claiming that they can't keep track of all the illegals to round them up but then they are sure they can keep track of them enough to get $2000 from each! This plan could ONLY come from Washington (or California).
Here's the article about the pissed off Union workers.