Should illegal immigrants be allowed to stay in the U.S.

Alright so yes illegal immigrants do come here illegally but they are also literally part of the economy. "The U.S. civilian workforce includes 8 million unauthorized immigrants. [1]. So one reason I believe that they should stay is because they are part of our workforce. So if you were to punish all these immigrants who have made homes and families here, which I assume is by deportation. You would be taking away 8 million jobs which would completely devastate our economy. "The Social circles." [2]. All of these immigrants came here for one reason or another, maybe where they live is a war zone. Or they can't support there family where they live. Now that they have been here they have friends and family here that they would be separated from. Destroying those social circles would cause sorrow and distraught through millions and millions of people. I also strongly encourage that you watch the video about this argument that I posted at the bottom. It is part of my argument so it will explain my point. "Immigrant advocates today are strategically calling the $12,500 cost a "deportation tax.". Department of Homeland Security estimates that there are roughly 11 million illegal immigrants in the U.S. If you do the math, that would mean it would cost $137 billion to deport all illegal immigrants." [3]. 137 BILLION DOLLARS! That is a lot of money that would be punishing people that are just trying to save their families. All that money could be used for better things, like building a better immigration system that helps with immigrants, so they don't attempt to come to this country illegally. Don't get me wrong I don't support illegals coming in. But I also don't support kicking those out that have good intentions. Especially when you have the possibility of them just coming back in. "The problem is not immigration, per se. The problem is the "free lunch society" of Medicaid, disability, schools, foods stamps, etc., etc., that makes it desirable for masses of people to want to come to the US for handouts." [4]. This is just stating another reason why immigrants are rushing forth to come to the U.S. "154 foreign-born terrorists in the United States who killed 3,024 people in attacks from 1975 through the end of 2015. Ten of them were illegal immigrants, 54 were lawful permanent residents (LPR), 19 were students, 1 entered on a K-1 fiance"(e) visa, 20 were refugees, 4 were asylum seekers, 34 were tourists on various visas, and 3 were from Visa Waiver Program (VWP) countries. [5]. And also. "Only 10 illegal immigrants became terrorists, a minuscule 0.000038 percent of the 26.5 million who entered from 1975 through 2015." [5]. "Only one of those illegal immigrants, Ahmed Ajaj, actually succeeded in killing an American." [5] So only one of the ten illegals was only able to kill one person. That means that you had 0.0000038% chance of being killed by an illegal. Also would you mind showing evidence on how illegal immigrants are how you stated " Taking away chances for legitimate immigrants who in some cases have waited years through the legal immigration process to enter the country." Thanks http://www.pewresearch.org...... [1] https://www.ted.com...... [2] (That was the video) http://blog.chron.com...... [3] https://freedomoutpost.com...... [4] https://www.cato.org...... [5]