You can't be serious. Laws don't take effect because people "care" to obey them, but because they're enforced. We haven't been enforcing our laws. We certainly haven't been making more than a laughable attempt to secure the border.
I would argue that border security alone - serious border security, that is - would go a long way towards reducing the problem. But if you want to include employers as well, then I would also argue that under a guest worker plan not available to illegals, it would be possible to tighten the vise on employers just enough to light a fire under their butts to get them to want to shift towards legal workers rather than illegal ones. And like I said, once the process is jumpstarted, it will be much easier to maintain it.
Again, we have the difference where I think that as long as we reward illegals with jobs, we can't stop them. And you seem to think that if we are "nice", they will play by our rules.
Are you a Liberal? It looks like it.