Do you agree there is a problem? How do we fix it?
Alright, I'll reply seriously.
First, I agree with what others have said about the border not being as big a mess as some on the right like to claim. However, I do think there is a problem, and we can do better. I suggest a threefold strategy:
1. For those with connections already here, and who are neither convicted nor suspected of major crimes other than being here illegally, give them a reasonable and doable path to citizenship. For the children who were brought here young and have grown up American, just make them citizens right now. They are already in all but name.
2. Renegotiate NAFTA. Trump had the general idea that this trade agreement is pretty crappy and needs to be reworked was correct, though his execution was poor. The main reason that we have so much illegal immigration is that NAFTA made it not only profitable, but downright necessary for many people living in northern Mexico and Central America. We got lots of money for the wealthy in this country and in Mexico, but this is the tradeoff currently. It is possible to rework the deal so that the wealthy elites get less but still make a profit, while making it possible to the poor in those areas to make a better living where they are.
One wrinkle in this plan is that climate change will force more and more people northward. Long term, we should look to structuring the economy to absorb a great many people. I suggest that we look to employ them doing two things: first, to swell the ranks of our armed forces, especially in support positions. Second, we should start building carbon sequestration plants, where these people could work. Perhaps as a third, we might look to changing precipitation patterns or perhaps artificial irrigation in the upper plains and the upper midwest, which are likely to become the new breadbasket of North America.
As a corollary, we need to start acting like an empire and a superpower. We keep the peace in the world, we exact tribute. Our larger armed forces will give us the strength to do it, the payments from other countries will help pay down our debt and allow us to employ more immigrants.
3. Step up surveillance and other measures at the border. A wall by itself won't work, and I wouldn't spend any more time on it. We can act humanely while catching more immigrants. These people are a potential resource, we can use many of them if we do it right. Currently, by treating them badly, we make them not want to get caught. If getting caught instead means they'll get water, a basic medical exam and treatment, food, and no abuse, we will start catching more of these folks and we will be able to figure out who we can use and what to do with those who aren't so useful.