He built a political machine based on his cash and populism and has a lot of support among poorer voters who responded to his rural development programs.But Thaksin has used his political power to protect and expand his business interests; in April he stepped down and called snap elections because of a backlash, and massive protests in Bangkok, over his 'divestment' of some companies that were bought up mainly by members of his family.
It's also worth noting that Thaksin single-handedly turned civil rights protests by the country's Muslim minority, living in an area near the border with Malaysia, into a full-fledged insurrection. This can't have impressed the head of the armed forces, himself a Muslim.
The opposition refused to contest the election, and Thakin's party "Thai Rak Thai" ("Thai Loves Thai") won most of the seats. He probably would have beaten the opposition in a fair fight.
But the boycott had the desired effect of creating a stalemate that eventually led to Thaksin stepping down as PM and the entire Election Commission being fired and then charged in the courts, asked by Thailand's much-loved king to ensure stability.
Thaksin has re-emerged as PM in the runup to elections planned for next month; coup rumours have been circulating for some time. Most had been dismissed as Thaksin's allies trying to mobilize his base. Clearly there was more substance to the stories.
Thaksin was a centre-right populist, overthrown by a military backed by a king. The loser is Thailand's democracy, which had gone for 15 years without a coup - a record in a country that used to have about one a year.
The military is going to appoint a new PM and parliament, and a new constitution will be drafted and elections held within a year.