Should United States try to keep out all illegal aliens from Mexico? Why or why not

Immigrants often "take" jobs from the people already living in the USA and some imma grants aren't seeking refuge but are using their residency to smuggle illegal things like drugs and people thru the border

Immigrants are often seeking refuge from gangs, drug cartels, and bad government/oppression and war. Sometimes people come to America for work and/or education or to start a new life.

This is really a matter of opinion. I'm from Texas and am very familiar with illegal immigration and am for immigration but I believe that illegal immigration needs to be controlled more.