Two of the major issues that are raging in the United States right now appear unrelated on the surface, but are keenly connected when one looks a little deeper. A new documentary film from reporter Sara Carter, “Not in Vein,” tackles the intersection of border control and opioid addiction in a terrifying light that reveals how Mexican drug cartels are terrorizing Americans with the most deadly drugs on the market.

While Democrats and Republicans are divided about border enforcement, they are united in combating the opioid epidemic. President Trump just signed a massive multi-billion-dollar opioid package into law after the House and Senate almost unanimously passed the bill. However, many members of Congress fail to see strong border controls as a way to stop the hemorrhaging of American lives through opioid overdoses.

As documentarian and journalist Carter highlights in “Not in Vein,” thousands of pounds of heroin cross the U.S. southern border on the backs of Mexican drug cartels every single day. The cartels risk execution from their superiors if they fail to deliver, and the multi-billion-dollar drug-trafficking industry keeps the drugs moving throughout the States to key locations.

From these hot spots — places like Dayton, Ohio — drug traffickers find contacts, distributors, and customers, and the whole process has a trickle-down effect, eventually delivering bags of opioids into the hands of high schoolers who have no idea how powerful these drugs are.

And heroin isn’t just heroin anymore. It’s often laced with Fentanyl — a substance that can kill you with an amount as little as 2 grains of salt. Fentanyl has contributed to rising death rates and, as one DEA officer said, could “literally be used a weapon of mass destruction.”

The same officer called the Mexican drug cartels “the greatest threat to the U.S.” In fact, in Nebraska recently, a tractor trailer was pulled over with 118 pounds of Fentanyl — enough to kill 26 million people.

“Not in Vein” also features interviews with ICE and undercover police officers working on the southern border to combat the cartels. The job is dangerous, and it’s nearly impossible to keep people from crossing obscure border lines that stretch for miles on hillsides without physical barriers. One farmer with land on the border said if he sees the cartels on his property, he simply turns around and goes the other way for fear of losing his life.

An undercover officer who declined to be named said you can never guess who will be carrying the drugs — it could be a child as young as 12 or a grandmother. The cartels recognize zero boundaries in ensuring their drugs reach the market and continue the cash flow back to Mexico.

At times, members of the group will cut their hair, change their clothes and cross the border claiming to be 17. With no way to verify age, they are taken in by border agents and eventually land in local high schools, where they begin to recruit new distributors and customers.

While Democrats often claim they do not believe in open borders, some of their rhetoric and actions say otherwise. Ranking Democratic Rep. Keith Ellison recently wore a T-shirt that said, “I don’t believe in borders,” and others have taken to saying Immigration and Customs Enforcement agents are “cruel and inhumane” for doing their job.

These lawmakers ought to consider how their position on immigration may be making it harder to fight the opioid crisis. They would do well to become informed about the role that a porous border plays in our nation’s drug abuse problems, and watching “Not in Vein” would be a good place to start.

There are no easy answers to immigration reform and border enforcement over a wide expanse of territory. We must accept people seeking asylum and maintain our country’s reputation as a place of refuge and freedom. But we should all favor securing the border against dangerous individuals in the business of dealing and dashing, with no regard for human lives. After all, the U.S. cannot continue to be a beacon of freedom to the rest of the world if we are overcome by our drug crisis.