Many of the more extreme libertarians have an "open borders" philosophy
"This is the very ugly, very racist tirade of Sharron Angle the so-called Tea Party candidate in Nevada. Any libertarian who is still defending this disgusting movement has either not been paying attention or is brain dead. The Tea Party is anti-liberty. They are bigoted against immigrants and gays and are actually worse on social liberty than your normal Republican. Surveys show that the Tea Party is mainly the most reactionary element of the Republican Party.
Angle, who is also a staunch anti-gay bigot, of course, claims that "waves" of Mexicans are coming to America. Actually immigration flows are way down because these people came looking for jobs and when jobs dry up they go back. But in Angle's fevered, bigoted, little brain these people are not coming to America for work but for the explicit purpose of "joining violent gangs, forcing families to live in fear."
The argumentation by the libertarian above is VERY weak. It is true that the rate of illegal immigration varies but that is not to stay that it stops. Whether the "wave" is large or small, there still are such waves coming in.
As testimony to how weak his argument is, the writer erects a straw man. According to him the advertisement claims that illegals are coming for "the explicit purpose" of joining gangs. Nowhere in the advertisement does it say that. It just lists gang joining as one of the things that they do. And there are indeed many illegal immigrant gang members whom America could well do without.
And NOWHERE does the author offer any evidence of a racist motive. It is just a smear.
Some libertarians can be as fanatical and doctrinaire as any Leftist. It's sad when you have an ideology to defend. Conservatives just go with reality so don't need to lie. And reality never justifies unfettered liberty.