Economics of Immigration

The Republican candidate for governor in Oregon is running television ads proudly proclaiming that he thinks "illegal means illegal" and so if elected he will crack down on illegal immigrants.

As I've indicated in previous posts, I'm rather radical when it comes to immigration. I think the problem with "illegal immigrants" is with the "illegal" not with the immigrants. To me, closing our borders (literally!) to immigrant workers is just another way for the rich to oppress the poor.

It probably wouldn't change my opinion, but I'd like to at least know what the economic trade-offs are. I know very little about economics, but it seems to me that welcoming immigrants should be good for our economy in the long run. If our wealth as a nation is based on what we produce then increasing the number of workers should increase our overall wealth, right? That is, of course, assuming that the incoming workers don't simply displace existing workers.

According to the aforementioned ad, there are 175,000 illegal immigrants living in Oregon. I can't imagine that we'd be helped by running them out of town. I strongly suspect that our economy depends on the work they do. So why does this Republican want to "get tough" with them?

My sense is that conservative politicians don't really care about this issue and are just using it to maintain the inexplicable support they have from blue collar workers who are afraid that their jobs and/or wages will be hurt by immigration. But what if this fear is well-founded? I don't want to be just another knee-jerk liberal who is unwittingly hurting one group of working class people in the name of helping another.

Does anybody have a good source explaining the actual economic issues involved?