Whilst I appreciate the sentiment behind the idea of militias that guarantee the citizens' freedoms, it is a rather touching fantasy.

One of the best examples for why is the United States herself. Some time past, a group of peoples/their representative states decided they didn't like the way the social contact was going and decided to opt out. Another group of peoples/representative states decided they rather fancied the idea of imposing their version of the contract on the recalcitrant. Inevitably, they had a Civil War about the issue and guess what? Those who had overwhelming control of government assets stomped all over the romantics, despite the latter being better led.

Plus ça change. Insurgencies may irritate governments but whilst those governments control the armies and the means of production, it's tough to overthrow them. Most especially if that government has become tyrannical (inevitably less squeamish) and far more so these days with their hold over modern weaponry. When the Constitution was written, it was still just possible to eject an unwelcome tyranny by militia - as long as it had a four thousand mile supply chain and a mad king. Nowadays I suspect one will find those helpful conditions somewhat scarce.

It took us eight hundred years to change the occupation of a foreign government that the majority of the Irish people hated. And it took terrorists to do it (and the development of a kinder, gentler, more civilised Britain) rather than well-regulated militas.