To hell with a replacement. Just get rid of DHS. The department really has done nothing special that couldn't be handled just as effectively by other departments. Hmmm, DOD comes to mind... DHS was unfortunate, it was a department established by Bush to consolidate authority. So far it's track record has been nothing but jack boot type tactics to steal individual freedom away from the American people.
+1 It just added more bureaucrats to the system.