The White House says members of the National Guard are on their way to the southern border and could soon be patrolling the border.

But despite the controversy, this action wouldn’t be the first time a president sent forces down to the border.

A UTRGV professor that specializes in public affairs and security said that in the past, both presidents Bush and Obama sent members of the National Guard to assist U.S. Customs and Border Protection.

The difference here is that they did not act as law enforcement personnel.

“Mostly surveillance. But basically, they’re going to be eyes and ears on the border to help CBP find people that are crossing the border illegally,” said Terrance Garrett, UTRGV professor.

In both of those deployments soldiers had no authority to detain immigrants because federal law prohibits using active duty troops to conduct law enforcement activities in the united states, unless authorized by congress.

Governor Greg Abbott also responded to the Trump administration’s controversial announcement on Wednesday afternoon.

He praised the move saying, “Today’s action by the trump administration reinforces Texas’ longstanding commitment to secure our southern border and uphold the rule of law, and I welcome the support.”