Mexicans aren’t stealing your jobs. Rich people are. If you want to ban immigrants for economic reasons, you might as well ban children too. Because if an increase in population ruins the economy, it would make sense not to increase it. But luckily that is not the case. An increase in population creates jobs. Each additional person needs food, shelter, and plenty of other things. The higher the demand, the higher the need for labor.
Besides, illegal immigrants usually take the jobs you’d rather not do anyway. Unless you aspire to be a janitor, you shouldn’t be complaining. The only problem is that they don’t pay taxes. But of course this would change if all immigration was legalized. There is absolutely no reason for an immigration ban.
If you are concerned about national security, first you should know that your country of origin doesn’t make you more prone to being a psychopath. Psychopaths are just as easily born in the US as they are in other places. While it is true that some people may be motivated by political agendas, immigration bans do not help to prevent this. If someone truly wanted to bomb a US government building, they would find a way into the country regardless of whether or not they were banned from it. If broke Mexicans can enter the country illegally, so can rich terrorist organizations. There’s no reason to follow the US laws if your plan is to break it anyway.