You are posting a serious question in a subreddit that is run by anti-Trump, pro-Sanders trolls.
I'm a moderator of a pro-Trump subreddit and will answer your question.
If the lines are "arbitrary" then why have nations and borders at all? You wouldn't be kicked out under Trump, no way that gets through Congress. Illegal immigrant families who, perhaps, don't have an anchor baby older than 5 or so? Yeah, even I say get them out of here but that would be close to impossible to get through Congress.
My wife came here legally. Accommodating illegal immigrants is an insult to her and the whole process she went through. This includes background checks, interviews, health assessment, fees, and lots of her time. Illegal immigrants commit more crimes, depress wages, overall put a burden on our system especially at the local level with things like public schools. Mexico, where 2/3 of the illegal population originated from (more if you count other Latin Americans who crossed over the Mexican border), gets to enjoy fewer criminals in its country, fewer desperate people in its slums, and more money coming back with remittances. Illegal immigration is a total win for Mexico, for the United States Chamber of Commerce, and for the Democrats as they benefit from the demographics shift as people come here with the same economic values that caused them to flee. Illegal immigration hurts everyone here with the crime, and it hurts the low-educated and low-skilled workforce in the US most of all.
If everyone who wanted to live in the US was able to just come then this country would be fundamentally transformed at the voting booth and it would no longer be the special place it has been. We need limited, legal immigration to continue but at a slow enough pace to give time for the immigrants to assimilate into our society. This can take a few generations.
We need to stop illegal immigration. We also need to stop the practice where well-off Chinese families pay upwards of $60,000 to go on "maternity tours" in the US in order to give birth to US citizens. We can repeal birthright citizenship for children of those who are not legal residents or citizens through an act of Congress. It would not require an amendment. We really need to get this done.