President Barack Obama's secretary of Homeland Security criticized the presidential Democratic candidates who have come out in support of decriminalizing illegal border crossings.

Julián Castro, Obama's secretary of Housing and Urban Development, has called for the repeal of Section 1325 in Title 8 of the U.S. Code, which makes it a misdemeanor for migrants to enter the United States illegally.

In his recently released immigration plan, New Jersey Sen. Cory Booker said he would "virtually eliminate" all immigrant detention centers.

"That is tantamount to declaring publicly that we have open borders," Jeh Johnson told the Washington Post. "That is unworkable, unwise and does not have the support of a majority of American people or the Congress, and if we had such a policy, instead of 100,000 apprehensions a month, it will be multiples of that."

Johnson has rebutted Democratic talking points when it comes to issues at the border. With renewed attention to the conditions and overcrowding at detention centers, he said those problems did not start when Donald Trump became president.

“Chain link barriers, partitions, fences, cages, whatever you want to call them, were not invented on January 20, 2017, okay?" Jeh Johnson said at the Aspen Ideas Festival last week.

"But during that 72-hour period, when you have something that is a multiple — like four times — of what you’re accustomed to in the existing infrastructure, you’ve got to find places quickly to put kids. You can't just dump 7-year-old kids on the streets of McAllen or El Paso," he continued. "And so these facilities were erected … they put those chain link partitions up so you could segregate young women from young men, kids from adults, until they were either released or transferred to HHS."