I look at the person, not their status. If an immigrant is working hard, contributing to society and not harming anyone, then I don't care how they got here. Undocumented status does not at all suggest to me that someone is a bad person or harmful to society. Most immigrants don't come here to start trouble or to take advantage of us. They come here because they left bad situations and want to make a better life for themselves and their families. Once they get that, they are not going to turn themselves in and be returned to hell. They are going to take a chance of not getting caught. I am pretty sure you would too.
That is not to say I want "open borders". That would cause all kinds of logistics problems. What I would like to see is a better immigration system moving forward.