You should check out how Mussolini came to power.

Long story short: he marched on Rome with a handful of wackos, the royal army absolutely had the power to wipe them out without breaking a sweat, but the king decided that baldy was a cool guy and handed him the government. Many people liked him.

Hardly a military action, and he went on to govern for 20 years, a streak that stopped only because he chose to stand on the wrong side of history, unlike, say, Franco.