Former commissioner of U.S. Customs and Border Protection Gil Kerlikowske told CNN anchor Poppy Harlow on Monday that the number of migrants crossing the border constitutes a crisis.

"So this is a crisis, and for anyone on either side of the policy aisle that said it's not a crisis, these numbers are a crisis and the workload is tremendous," said Kerlikowske, who served in the Obama administration.

U.S. officials have said that border agents are overwhelmed by the number of migrants crossing the border. Border apprehensions hit a record high last month with 98,977 arrests. On Wednesday, border agents apprehended a group of 1,036 migrants illegally crossing from Mexico, the largest group arrested this fiscal year.

Democrats in Congress have been slow to recognize reality at the border.

Sen. Richard Blumenthal (D., Conn.) and Rep. Bennie Thompson (D., Miss.), chairman of the House Homeland Security Committee, are among those who have accused the president of manufacturing a crisis.

"Undocumented border crossings are at *near historic* lows. There IS no emergency," Thompson's committee tweeted in February after President Trump declared a national emergency at the border.

Democrats running for president have been reluctant to offer their own positions on immigration, with only three of the 24 candidates posting a full immigration proposal on their websites, and only nine having some sort of immigration proposal listed.