[vannevar]

Rational arguments seldom make their way into this discussion, if it can be called that. On the one side we have the empathetic liberals...

It's a common misconception among conservatives that progressive policies are driven solely by emotion, out of compassion and empathy. In fact, progressive policies are pragmatic, driven by sound economics based on long experience. Policies like the minimum wage aren't in place solely to give poor working families more money; they are in place to prevent just the sort of economically destructive race to the bottom that you use as a rationale for limiting immigration. With a strongly enforced minimum wage, workers compete to deliver better service, not to get lower wages. This prevents the decline that you speculate accompanies permissive immigration. Progressive taxation policies are similarly pragmatic and economically sound---despite the knee-jerk emotional reaction conservatives have to taxation, no substantial correlation has ever been found between tax rates and economic growth.