The rule in American government is that only solutions that will be considered to any political problem must involve spending more money. If you want to shut down Homeland Security, I would suggest proposing replacing it with a new agency that can spend more money than Homeland Security is currently spending.
Wouldn't that be the same as just renaming the agency? It's going to be comprised of the same career people and contracting companies anyway. There needs to be hard restrictions on their powers.