The Canadian border is also weakly defended, but the Canadians, as boring as they are, do not show overt official hostility (unless conected to the Loony Left) to the US and actually make a game try at enforcing the law with very limited resources.
Actually, they don't. Their immigration enforcement makes our efforts look much better than they actually are.
Canada has had its chance at freedom and rejected it as Robert Taft the Elder said of Europe in 1948. Mexico's freedom lies ahead within Mexico's own borders and the defeat of the Institutional Revolutionary Party (yesteryear's killers of priests) was a key tio breaking the corruption. Apparently you believe that the PRI thugs who had 80 years to institutionalize, crime, corruption and half-communist economics can be rooted out in a few weeks.
As to Canada, can you spell T-R-U-D-E-A-U? He was the anti-American leader (sort of a Canadian Henry Wallace or George McGovern) of the same party that rules in Ottawa today. Chretien is a modern morph of Trudeau.