http://transcripts.cnn.com/TRANSCRIPTS/ ... dt.01.html

DOBBS: The Homeland Security officials say they're prepared to deal with cartel violence or a mass exodus from Mexico, but they offered no specifics.

(BEGIN VIDEO CLIP)

JAYSON AHERN, CUSTOMS & BORDER PROTECTION: Every single one of our ports of entry, every one of our southwest border stations and sectors actually have contingency plans, if we start to see triggers occurring south of the border, it could indicate there might be a mass exodus from Mexico or a running gun battle, if you will, coming across that border.

(END VIDEO CLIP)

DOBBS: Not a single person in Congress asked those officials that if they have this plan for a mass exodus, refugees, violence along the border, why if they could do that, they weren't stopping the flow of illegal immigration and illegal drugs across that border now. I wonder why they didn't ask that question.

The reality at the border is that illegal drugs continue to flow freely into this country. Mexico is the principle source of marijuana, methamphetamine, cocaine and heroin into the United States. Only a portion of our border with Mexico is secured by a fence. That could be because fences work.

Drugs smugglers working for the cartels continuously find new ways to bring their contraband into this country. Casey Wian reports from one of the most notoriously smuggling points all along the U.S./Mexico border, this one near (INAUDIBLE).

(BEGIN VIDEOTAPE)

CASEY WIAN, CNN CORRESPONDENT (voice-over): The construction of 670 miles of new fencing along the nearly 2,000 mile U.S./Mexico border is nearly complete. Physical barriers, roads, cameras and sensors have all forced Mexican drug cartels to change their tactics, but the flow of drugs across the border persists. Three dozen Republican lawmakers today wrote President Obama demanding that more fence be built, especially the double layered variety that has sharply reduced drug smuggling in places like San Diego.

REP. DUNCAN HUNTER (R-CA), HOUSE ARMED SERVICES COMMITTEE CHAIRMAN: There's only about 60 miles of double border fence built like we have in San Diego, the rest is vehicle barriers, single-layer fence, which is not as proven as a double border fence to stop illegal aliens, drug trafficking, terrorists from coming across the southern border.

WIAN: These pictures taken last week by a hidden game hunter's camera in the mountains south of Tucson, Arizona, show suspected drug smugglers carrying the large backpacks typical of the trade. Farther west near Yuma, Arizona Sunday, border patrol agents seized 800 pounds of marijuana in a camouflage utility trailer being towed by an all terrain vehicle through a wildlife refuge.

And in San Diego Customs and Border Protection says this year, it has experienced an 800-percent increase in the number of pedestrians crossing at the (INAUDIBLE) point of entry with drugs taped to their bodies. Most are young men wearing baggy multilayered clothing. About one in four are under 18 years old, the border patrol says its three-year efforts to deploy more manpower infrastructure and technology is working.

CHIEF DAVID AGUILAR, U.S. BORDER PATROL: That results in some of the in-fighting, some of the border violence that we're seeing. They are fighting for territory that they no longer operate within punity (ph).

WIAN: In Tijuana Monday more alleged cartel members were arrested, drug trafficking organizations are linked to 7,000 deaths in Mexico in the past two years.

(END VIDEOTAPE)

WIAN: And with violence spreading across the border more often Republican lawmakers are saying now is no time to stop border fence construction. And Lou, more evidence tonight of just how bad that violence is becoming, police in Mexico near the city of Gualahara (ph) discovered these five ice chests off the side of a road. Each ice chest contained a severed human head. Police say that those heads were severed only about four hours before they were discovered. Beheadings of course becoming increasingly common intimidation tactic used by Mexican drug cartels -- Lou.

DOBBS: The violence has been ongoing now for two years, 8,000 Mexican citizens killed. Kidnapping -- Mexico is the kidnapping capital of the world as well. Extraordinary when you think about all of the places in which terrorism does exist. Phoenix is now the kidnapping capital of the United States and yet at the same time, David Aguilar (ph), the head of border patrol sits there and says the reason there's so much violence is because that fence has been put up and they've been so successful. So the question becomes why don't they in point of fact fence the entire 2,000 miles of that border with Mexico as a humanitarian gesture for Mexico which would then stop the violence.

WIAN: That's what a lot of Republican lawmakers are saying they should do. The argument against that -- they've had several arguments against that, as you well know, Lou. One is them is that fences aren't effective in some places...

DOBBS: Yes, but we've just heard...

(CROSSTALK)

DOBBS: We've just heard -- you know that argument though Casey is over. That's bull. We know that. It's demonstrated. The fact is both sides have to admit the fence works. Whether they're -- you know no matter what their position on illegal aliens or amnesty or open borders, the fact is they don't want this fence completed because they're afraid that it's going to be entirely effective, which speaks to the corruption on the side of the Mexican border and to greed and perhaps corruption as well and ethnocentric interests on this side of the border. What do you think?

WIAN: Well, I think that's a good argument, Lou, and a fair argument, but they do say that there are places where the fence is not necessary. There's places where it is more desperately needed and that's where they're putting it first.