The Mine Resistant Ambush Protected (commonly known as the MRAP) was developed and rushed into production to protect soldiers and Marines in Iraq and Afghanistan from large Improvised Explosive Devices (IEDs). IEDs were made primarily of artillery shells, copper shaped charge penetrators, and large bombs made of fertilizer & fuel oil. The IEDs were getting so large and so sophisticated that the heavily up-armored HMMVW were no longer effective protection. Now a up-armored HMMVW is no regular car – it is a custom made armored vehicle that can take AK-47 fire and anti-tank mines while protecting the soldiers inside. There is currently zero threat in the USA from land mines, IEDs, and AK-47s being employed against anyone in the USA.
So when the Department of Homeland Security starts buying and using MRAPs solely for domestic use (the photos above were from California and Georgia) you have to ask who is the enemy. The military has the charter to protect the US from external threats, and can do that very well. DHS has a charter to take care of things internal to the country. Who is the emergent terrorist threat in the USA that requires MRAP?