Democrat presidential candidate Julián Castro told CNN’s Don Lemon that President Trump’s tariff threats are “Grade-A dumb.”

The former Obama official spoke with Lemon on Tuesday night, primarily to discuss his “People First Policing Plan.” It’s a three-fold idea, which focuses on ending “racially discriminatory” policing, prioritizing officer accountability, and fostering a “healing process” between communities and police departments.

“Even though we have some great police officers out there, and I know that because I served as mayor of San Antonio, this is not a case of just a few bad apples,” Castro told Lemon. “The system is broken.”

The conversation dipped into other areas, including President Trump’s recent threats to levy a five percent tariff on Mexico until the country makes serious moves to halt the flow of illegal migrants at the southern border.

Castro called the idea “Grade-A dumb” and asserted that the threat has “nothing to do” with trying to get Mexico to secure its border.

“What will tariffs actually accomplish?” Lemon asked.

“First of all, this is a stupid idea,” Castro said. “This is Grade-A dumb in terms of ideas. It’s not connected to trying to get Mexico to do anything. I think we can do this in a better way.”

“It’s already estimated that this five percent tariff, to begin with, that he wants to impose on Mexico will cost 400,000 jobs nationwide, and 100,000 of those would be in my home state of Texas,” Castro continued.

“And so, this is the worst possible way to go about partnering with Mexico to get them to do anything,” he added. “In fact, it’s just going to hurt the United States.”

Trump’s erratic trade fued is grade-A stupid. It will do nothing to fix the humanitarian crisis created by his immigration agenda, and will hurt American workers in the process. pic.twitter.com/CY5oC1qx2V — Julián Castro (@JulianCastro) June 5, 2019

Sen. Lindsey Graham spoke on Fox News Channel’s Fox News @ Night Tuesday and explained why he’s not among those who oppose Trump’s tariff threats.

“Tariffs would be tough on the economy,” Graham said. “But the borders are broken that needs to be fixed. And if tariffs is what it takes to get Mexico to do better on their side of the border, I’m all for tariffs.”

“Trump is not the problem,” he continued. “Mexico is the problem. Republicans are not the problem. Democrats won’t vote to change the laws.”

Trump is continuing to stand his ground and insists that he’s not “bluffing.”

“Can you imagine Cryin’ Chuck Schumer saying out loud, for all to hear, that I am bluffing with respect to putting Tariffs on Mexico,” Trump tweeted Tuesday night. “What a Creep. He would rather have our Country fail with drugs & Immigration than give Republicans a win. But he gave Mexico bad advice, no bluff!”