The US immigration system is a complete joke. You can not get legal status or have a path to citizenship if you entered illegally. People who had Visa's revoked or stayed past expiration have to leave the country voluntarily, then re apply after a set amount of time, typically 10 years. If you re enter illegally after deportation, it is 20 years.

Edit: I forgot to answer your first question. There is no argument against deportation. Most reasonable people would, and have, argued that the immigration system needs overhauled to allow people to work towards citizenship or legal status. It is and has always been a clusterfuck of paperwork and arcane rules. The main argument is how you deport people. Here are several examples: ICE raids a Georgia/ South Korea venture billion dollar solar panel factory. They show up with dressed as para military, full swat gear and arrest 300 South Koreans at the plant. Handcuff and parade the workers out to detention, then deported. The workers legally entered the country with B1 business Visas. They are not here to take an American job, but to set up equipment and train the US workers in the new venture that is slated to open next year. The Trump administration argues that they should have had H1b Visa's instead and made a big show of a raid. The detention conditions are also terrible. Not one of these workers will ever come back to the US, and we may have stifled foreign investment in the future. The simple solution is to contact the Korean corporate office and convert everyone to a different Visa. Many other companies have used B1 in the past, and if they want to change interpretation, so be it, but to go about it like a raid on a terrorist cell is ridiculous.

Example 2: ICE raids a South Chicago apartment building in the middle of the night. They repelled from Blackhawks, had drones and used 300 federal agents dressed as paramilitary soldiers. They kicked in doors and used flashbangs and tear gas. All residents of the 130 unit building were detained, including children, outdoors and with little to no clothes. In the end, they arrested 37 illegals, of which no one has found a criminal record for. No one has been charged for any crime. Multiple Venezuelans were deported out of the 37, for a civil offense (not criminal).