I’d definitely recommend that you give Kerry Howley’s Reason article on guest workers in Singapore a read. It’s a very thorough and balanced discussion of the way it works. That said, given that the crux of the opposition to such programs for the United States is “it’s repugnant and un-American, violating everything this country stands for” to say in reply but look at how well it works in a small, regimented, highly inegalitarian Asian dictatorship doesn’t seem very persuasive.
The experience of a more similar society, Germany, is not something that many Americans look at and would desire to replicate. Meanwhile, I have no desire to see the United States become more like Singapore. We are, however, in the midst of a burgeoning libertarians against democracy moment (a return to classical liberalism’s traditional anti-democratic sentiments) of sorts, so maybe we’ll start seeing more and more aspects of Singapore and Hong Kong recommended to us as models.