One of the reasons it is so difficult to address the immigration problem is that we can't even agree on what the problem is. There are several reasons why the problem is so hard to define.
Conservative Point of View
For example, if your point of view falls towards the right end of the political American spectrum, you will probably hold the following beliefs about immigration:
2) If you have come to the US illegally, you are a criminal.
3) Illegal immigrants are responsible for most of our crime.
4) Illegal immigrants are receiving free services at taxpayer expense
5) Illegal immigrants pay no taxes because they can't get social security cards.
6) Illegal immigrants come to the US to have children to entitle them to collect govt benefits
These are a few of the common complaints I hear from conservatives and others who want tougher sanctions against illegal immigration. There are others.
Liberal Point of View
1) Somewhere back in our ancestry, we were all immigrants (except, perhaps, the native Americans).
2) America is not only a land of immigrants, but if we want to keep the flame of liberty burning, we should welcome immigrants with open arms.
3) Immigration has nothing to do with unemployment
4) Most immigrants contribute more to America than they get from our government.
5) America's immigration policies should be changed to make it easier for people to immigrate to the US.
6) Calling undocumented aliens "illegal immigrants" is perjorative and intended to foster animosity towards them.
7) Those undocumented immigrants whose only crime was to cross the border should be provided a path to citizenship
Conservatives Moving to the Extreme Right
Again, there are more beliefs held in common by those whose ideology falls to the left of the right on the political spectrum. I say to the left of the right because the right has moved so far to the extreme side of the scale, the the center has become viewed as the left by many of those on the right.
Since there is unlikely to ever be agreement on what the immigration problem is, it is equally unlikely, and perhaps certain, that it will never bs solved. The real problem isn't the immigration itself, but the difference in opinions that surround it.
It is true that additional people entering the work force through immigration alters the nature of the workforce AND the amount of services required by the government to maintain the social safety net. It is also true that the addition of workers to the workforce creates additional market demand and additional tax revenue for the goverment to provide those services.
Primary Causes of Unempmloyment