Here again we have an example of just how feeble the leftwing mind is.
There is a claim that some 90% of the weapons smuggled into Mexico come from the US. This is BS, and cannot be supported by any facts.
http://www.stratfor.com/weekly/20090708_mexico_economics_and_arms_trade
Then there is the claim that Mexican prisons allow inmates to be free at night to kill citizens, etc. Again, this is a claim against ONE mexican prison, and cannot be proven by facts. Notably, the Mexican judicial system is corrupt, as is the government itself, however, one should rely on facts, not speculation.
Securing the border, which the leftist mind objects to, would be the ONLY way to insure that guns are not smuggled South, and that drugs are not smuggled North. However, the leftist mentality would prefer to allow the borders to be open, and they would rather legalize drugs, and give illegals amnesty, instead of truely doing something that would curtail, not eliminate of course, the problem.