Without guns we're defenseless to a tyranical government takeover. That's pretty much why there's an amendment in the Bill of Rights about it. There are and have been countless governments who have bullied their own people because they were stronger.
The government should fear the people, not the other way around.
Do you honestly believe that 'the people' will all unite and each with a handgun will be able to face the might of the government with their millitary funded machinery and equipment?
I don't really think that the USA is in threat of a 'tyranical government takeover', so I don't see this as a valid arguement for the upholiding of firearms in society.