The problem in comparing earlier immigration groups and the illegal immigrants of today is that the immigrants from WW1 & WWII still had to go thru the process of learning to speak/spell english, learn the US's history, at least a basic amount, and several other processes. The illegals today are bypassing that process. While immigration is all well and good, going thru the processes to EARN citizenship is just as, if not more, important as a government and countries populace's ability to accept them. In other countries, the policy for illegals is shoot to kill and the immigrants go thru the process for fear of death. In this country, that threat is removed, and without punishment, people have taken advantage of the governments trust in other countries citizens.
My conclusion is this:
Borders should increase their security, perhaps to a lethal extent. However, the process should be incouraged to promote growth.