If you want to rely on penalties than admit that many legal immigrants (or Reagan legalized aliens) are happy to house and abet illegals here simply because the life is easier here and they can send money home to help build the family finca...after all, it worked for the last round of invaders.
Penalties should be extended to ANY US citizen or legal resident aiding or abetting the invaders in the same manner as employers should be penalized for hiring illegals.
Of course, we also need a wall, surveillance, and armed troops along our southern border.
BUT, once the southern border is tightened up it will be necessary to ramp up efforts on the northern border because terrorists and smugglers will exploit our one truely friendly border.
You mean to put a wall down the middle of the Rio Grande?? A good project for the WPA.