A Fence Between U.S. and Mexico

Regarding the immigration reform effort, Charles Krauthammer wrote that enforcement should come before amnesty (yes, he used that word) and that the border should be secured by accomplishing the following:

With three obvious enforcement measures: (a) a universal E-Verify system by which employers must check the legal status of all their hires; (b) an effective system for tracking those who have overstayed their visas; and (c) closure of the southern border, mainly with the kind of triple fence that has proved so successful near San Diego

People!  The fence.  The fence.  What's with the fence?  Does he realize the U.S. Mexico border is 1,933 miles.  That's a lot of fence, and triple that if you want to follow Krauthammer's suggestion.  One can build all the fences and walls you want, but maybe he should heed his fellow conservative Rick Perry who back in 2011 in NH famously (and correctly noted):  “No, I don’t support a fence on the border...The fact is, it’s 1,200 miles from Brownsville to El Paso. Two things: How long you think it would take to build that? And then if you build a 30-foot wall from El Paso to Brownsville, the 35-foot ladder business gets real good.”  How about turning off the main magnet for undocumented immigration by actually enforcing employer sanction laws that are already on the books?