It is the enduring paradox of politics in Thailand.

By several measures, it appears democratic — it is a constitutional monarchy that holds regular, competitive elections with high voter turnout and a young generation that is politically active. In practice, analysts say, the country is beholden to an unelected establishment comprising the powerful military, judiciary and the royal family.

Thailand has experienced more than a dozen coups since absolute monarchy ended in 1932. This constant tussle between movements to create democratic reform and the power of the old guard has created a decades-long cycle of instability.

Few people know this as intimately as the Shinawatra family, which has been at the center of the most dramatic moments in Thai politics in the past 20 years. On Friday, Paetongtarn Shinawatra became the latest prime minister to be removed by the Constitutional Court.

Here’s what you need to know.

One Powerful Court

The Constitutional Court has tended to deliver rulings that produce outcomes seen to be broadly aligned with the interests of the establishment, according to Napon Jatusripitak, a visiting fellow with the Thailand Studies Program at Singapore’s ISEAS-Yusof Ishak Institute.

This stems from the court’s identity and its makeup. The court has come to be seen by conservatives as “a moral vanguard protecting Thailand’s pillar institutions against what it perceives as democratic excesses,” Mr. Napon said.