Seriously if the US government wanted to suppress its population t would use its (very large) selection of special weapons and survellience equipment.
Look at Iraq - the population were just as well armed and militariezed under Saddam as them are not, its not acccess to weapons that allows populations to rise against oppressive regimes but a nesscessary driving force and an ability to organise.

Does your definition of everyone being allowed a gun also apply to potential terrorist, child molsetors, mentally unstable people....etc.
And before you argue if everyone had guns they'd be dealt with - one well trained motivated individual can overcome several untrained panicked ones.

Do I advocate banning guns? No
But it makes sense that if you have to get a driving licence you should have to aget a gun licence.