Obama border patrol chief reveals the inconvenient truth about border walls. Democrats will not be happy.

Mark Morgan, who served as chief of the Border Patrol during the Obama administration, explained Monday on Fox News the practicality of a border wall.

President Donald Trump insists a wall be built on the U.S.-Mexico border to maintain national security.

What did Morgan say?

Speaking with Fox News host Tucker Carlson, Morgan was frank about the effectiveness of border barriers.

"Yes, they absolutely work," Morgan said, noting that before Trump became president, increased border security measures enjoyed bipartisan support.

"If you look in the past, you don't have to go too far back in history that bipartisan legislation that was passed, the Secure Fence Act. In 2006 and 2016, bipartisan legislation passed where they built the wall or fence or physical barrier — whatever you want to call it," he explained.

"It's a wall — it works," Morgan emphasized.

Owing in part to their staunch opposition to Trump, Democrats have refused to compromise with the president on border security, resulting in a partial government shutdown. Trump said he will not approve spending bills without funding for the wall, while Democrats say they won't approve the funding.

But, according to Morgan, there is no sensible reason to oppose the wall. In fact, Morgan — whom Trump fired in the early days of his administration — said "historical data" and "facts" confirm walls effectively mitigate illegal immigration.

"I cannot think of a legitimate argument why anyone would not support the wall," Morgan affirmed.

Mark Morgan, Obama's Border Patrol chief who was dismissed by the Trump admin, on if border walls work: "Yes, they absolutely work...that's based on historical data and facts that can be proven"

“I cannot think of a legitimate argument why anyone would not support the wall" pic.twitter.com/ZbKB91mlSU
— Ryan Saavedra (@RealSaavedra) January 8, 2019