A few people with small arms can force a more powerfully-armed government to either destroy a city or leave them alone. Warsaw and Budapest demonstrated that if a government is willing to destroy a city not much will stop it.
On the other hand, the U.S. has enough value in its cities that even a rogue government would be loathe to destroy them. Probably not so in Iraq.
I can conceive of a situation where Clinton would turn the military on us.
Actually, that argument also is a bit of a red herring, used to question the idea of an armed citizenry against the military.
A big factor is the will to fight, and the willingness to use arms. Let's postulate for a moment:
Let's say that the King, whom we'll call Planetarchis, decides to use the military and the quasi-military portions of the government in a bid to crush those voices that are in dissent. Let's also say that about an estimated 40% of the population owns firearms of some sort.
Now, of the general population, 30% never saw a dictator they didn't like, 30% are adamantly opposed to any attempts to usurp rights, and 40% are a mixed bag. Also, the 30% of the population opposed also tend to favor firearms.
So, where does one begin on their own soil? After the first initial forays, perhaps taking out a few large cities and crushing certain centers of rebellion, and neutralizing others by the use of agents, other areas of the country begin to solidify against the ursuping regime.
Now, there isn't any major offensive, but the rebels begin to lay ambushes ( imagine a contrived Waco that draws in a large quasi-military force, only that the area has been wired and manages to massacre a large portion of the forces deployed ), and that kindly little old lady that has baked cookies for some of the soldiers guarding against rebels, after liberally lacing them with ricin ( then subsequently disappears without a trace ),and that areas around several military base now have boobytrapped areas that have taken down planes ( with subsequent use of resources to patrol the surrounding areas, with the occasional exchange of gunfire ).
The leaders that have promoted this use of the military now are bunkered, and travel in armored vehicles to prevent a bullet from some 'rebel' armed with a scoped hunting rifle.
Sooner or later, elements of the military will begin to question the wisdom of fighting their own people.
The point is, this becomes a question of attrition, and the demoralizing effect upon the 'loyalist' soldiers who have to function from bases in territory that once was 'home', but now are not certain whether or not to trust the locals.
In the end, it becomes a crapshoot. I could go on with possible outcomes, but if the general population is armed, and the government has no foreknowledge to conduct a preemptive 'Night of the Long Knives' on those who own those arms, there is a large disincentive for those in government to use the military on the general population.
Remember Waco? Posse Comitas notwithstanding.