I do not have a real good answer for that, it is not a problem open to easy solutions. I support a DACA/DREAM type act. If you where brought over(as opposed to coming over of your own volition) as a minor, jump through hoops, stay out of trouble and show evidence via college or military service that you will be an asset to this country, I think we would be foolish not to let them get at the back of the line to citizenship. I would limit it to a certain number per year(best applicants only) who can join the program, but I have no problem with it.
I think the wall/fence idea is a waste of resources that could be better spent elsewhere. As long as the reward for entering the country is so high, people are going to find ways to do it. No wall, fence or whatever is going to stop them. So to me, the best way to keep people out is to go at the problem from the other end, by lowering the reward for entering the country. That means going after those who employ illegals, hard. The penalties have to be raised for employing illegals, the employers need better tools to identify illegals, and enforcement should focus on finding where illegals work.
There are a ****load of practical problems with just up and removing all the illegals. It would be nearly impossible, if not impossible, it would cost a ****ton of money, and the removal of 10 + million consumers would do bad things to the economy. That does not mean stopping deportation, it means that tracking illegals who are, other than being in the country illegally, not breaking laws is misplacing resources. However, illegals encountered by law enforcement should be deported. Illegals who commit crimes should be deported. There is a difference between turning a blind eye, and not actively seeking them out. If you find illegals, deport them, but looking for them specifically is alot of money for small return.
My views on all this are evolving some as I learn more. Like I said to start, I do not have good answers, only kinda generalized ideas. The big thing is I think until we limit employment prospects for illegals, we are never going to stop the flow into this country.