The weakest argument for gun ownership in the USA

[PowerWizard]

You contradict yourself a bit where you argue that gun-ownership allows extremists to form paramilitary groups to overthrow the government, and then on the other hand you argue guns are uselses to civilians since they could never defeat their government in a fight should it become tyrannical.

Extremists and normal civilians are two different kinds of groups, I hope we agree. These are two separate issues, there's no contradiction.

Also the fact, Marines will join the population.

It is light years far from being a fact, it is your personal opinion that lacks any kind of proof. The fact is that Marines will do anything they are told, because blind obedience is in their code of honour, that's how they are trained. If they are told, that evil men funded and staffed by terrorist organizations are willing to overthrow the federal government and establish a Muslim Republic, they won't hesitate shooting their own compatriots.

How much power do you want the state to have? If the state becomes too strong, you are defenceless.

Presuming the state is intentionally acting against the interests of the people, moreover wants to oppress them. Why would you presume that?