Senator Ruben Gallego of Arizona, a Democrat, spoke Wednesday on MS NOW’s Morning Joe. He said the Department of Homeland Security has suffered internal problems for years, which allowed some officials to remain.

He called for reshaping the agency into an immigration operation that removes people who should not stay and retains those who should. He said Democrats previously failed to handle the department and treated it as someone else’s concern.

Gallego said the party must now take responsibility, identify who leads the agency, and pass measures to resolve immigration difficulties that have lasted decades, based on his time in the Obama administration.