I mean, there's at least 50 legal points of entry along the southern border, which is under 2000 miles long.
The current laws deport most of those who file for asylum. There is no temporary work permits, so for those who want to either find temporary work, or stay in the USA (usually with friends or family who are already in the USA) they have a better chance of staying long term by avoiding the system. I have a friend who entered the USA about 20 years ago when he was 17, coming from El Salvador. He was a bike racer and had his own business, along with a wife and child. By all accounts he was a good citizen who paid taxes like anyone else. He was caught in a small Missouri town in a speed trap that was set at 15 mph. It was a notorious town known to make quite a bit of revenue with this absurd speed limit. Anyway Alex was now in the system, and he has a lawyer working his case. That he has a family and has not been in any trouble goes a long way. His case has been in the system for about 6 years now, and no resolution. He has faced deportation a few times but his lawyers have been able to stop it given his wife and child need his income, an for the sake of the child.
I personally asked him about why he crossed illegally. Many reasons. One was that migrants know the system is expensive and stressful, and like anyone other human we avoid stress. He had family in the USA that he could work for. Migrants know that once they are in the system and end up being deported, it is a closed door in the long run. He said El Salvador was extremely violent and gangs tried to get young boys involved whether they want to or not. Migrants know they have two options: enter and file for asylum and take their chances with the courts, or enter illegally and try to live under the radar. Alex took his chances as an undocumented person. And he got away with it for over a decade. His record and his lack of trouble gives him a chance to remain in the USA. If he is deported what happens to his family? Allow your Christian beliefs to guide your judgment here.
Alex is a good guy and well liked in the cycling community, and we can see that his personality would not fit with violent gangs. Unlike Trump's claims migrants aren't rapists and theives. Data shows most are good people seeking safe lives and better opportunies.
At this point the reform bill that Trump sabotaged is done. The only chance for reform is for democrats to regain congress and the presidency. Until then the law as it stands will not prevent border crossings, nor give migrants more hope to find a better life through legal channels.