Because there isn't any legitimate reason to turn away people seeking asylum or looking to immigrate. The issue with the process we have how intentionally slow and throttled it is. We can easily speed up the legalization process. Illegal immigration happens either from desperation or, most commonly, overstayed visas. Instead of treating this as a criminal act, we can simply have them begin the legalization process while staying in the country.

Even from an economic perspective immigrants are a benefit. However our intentional two-tier labor system is utilized by companies to hyperexploit illegal immigrants by threat of deportation. Legalization is critical to also institute labor protections. Along with unionization, this would also benefit American workers in those same industries with increased pay and benefits. Companies like to use the two-tier labor system to also justify lowering wages for the legal workers.

Not like the brazen giant of Greek fame, With conquering limbs astride from land to land; Here at our sea-washed, sunset gates shall stand A mighty woman with a torch, whose flame Is the imprisoned lightning, and her name Mother of Exiles. From her beacon-hand Glows world-wide welcome; her mild eyes command The air-bridged harbor that twin cities frame.

"Keep, ancient lands, your storied pomp!" cries she With silent lips. "Give me your tired, your poor, Your huddled masses yearning to breathe free, The wretched refuse of your teeming shore. Send these, the homeless, tempest-tost to me, I lift my lamp beside the golden door!"