It depends if the immigrant is hired because the native worker is deemed too expensive. In this case, it contributes to reducing contributions through wage suppression.

There is a good case for vetted legal immigration (there is need and they fill that unmet need), no question; however, that should not be at the expense of the local population, regardless of country. In other words, the locals should not suffer a depressed job market because of immigration. The whole reason for a state to exist is to first and foremost look after the wellbeing of its citizens that elect the bodies of government.