Several thousand people dressed in yellow or pink, colors associated with the royal family of Thailand, gathered along the road to the Grand Palace in Bangkok on Saturday to celebrate the birthday of King Bhumibol Adulyadej, who died in 2016.

Many more people have gathered at recent protests to call for the monarchy’s reform.

Last week a demonstration was supposed to take place outside the majestic yellow building that houses the Crown Property Bureau, the agency that manages the Thai royal family’s colossal fortune. In 2018, the current king and Bhumibol’s son, Maha Vajiralongkorn Bodindradebayavarangkun, claimed direct, personal control over those assets, estimated at $30 billion to $60 billion.

But after razor wire and road blocks went up around the vast compound, organizers changed the venue for the demonstration to the headquarters of Siam Commercial Bank: King Maha Vajiralongkorn is thought to be the bank’s largest single shareholder.

One of the protest leaders, Panupong Jadnok, had called for the gathering to “demand the return of taxpayers’ money.” In August, protesters put out a 10-point manifesto “to resolve the problems with the monarchy,” adding that it “must not hold power related to politics.”

Why, though, are the people of Thailand rising up against this king now when the previous one drastically restricted Thai democracy?

The kings of modern Thailand have sometimes exercised their royal prerogatives apparently at odds with existing laws. King Bhumibol, Vajiralongkorn’s father, intervened in politics occasionally but significantly, even though Thailand’s many constitutions over the years have defined the monarchy as being “yoo neua gaan meuang” or “above politics.”

The historian Thongchai Winichakul has argued that King Bhumibol’s reign redefined the meaning of that phrase: from staying out of politics to being on top of politics, or acting as the ultimate authority, superseding all laws.

King Bhumibol’s extrajudicial exercise of power wasn’t just tolerated by many Thais; it came to seem justified, even when it contravened the popular will as expressed in democratic elections. (During his 70-year reign, he endorsed a number of military coups.) Partly this was because of King Bhumibol’s status as a “dhammaraja,” a virtuous leader and god-king. He was also immensely popular, partly for spearheading development projects in marginalized regions and his personal outreach.

King Maha Vajiralongkorn, after just a few years on the throne, seems to have inherited his father’s practice of overriding formal limits on royal power, but not his spiritual aura, nor his ways.

King Bhumibol usually pursued his political objectives by acting at a slight remove, typically through the monarchy’s vast influence network, such as via the Privy Council. More problematically, he at times called on the judiciary, including in 2006, to annul the results of a democratic election.

But King Maha Vajiralongkorn has tended to intervene directly, without proxies.

Soon after he ascended to the throne in late 2016, he requested amendments to a new Constitution — which was essentially drafted by the military and approved in a nationwide referendum — so that he could rule Thailand from Germany, where he had been residing. Last year, he ordered by royal decree that two army units be placed under his direct command.

In the lead-up to the last elections in March 2019, the Thai Raksa Chart Party, a splinter group from the party of former Prime Minister Thaksin Shinawatra (who was deposed in a military coup in 2006) nominated Ubolratana Rajakanya Sirivadhana Varnavadi, the king’s older sister, as its candidate for prime minister. The king issued a royal order prohibiting her candidacy, while accusing Mr. Thaksin of jeopardizing the monarchy’s supposed apolitical position. The Constitutional Court then disbanded the party.

Last year, too, King Maha Vajiralongkorn elevated Sineenat Wongvajirapakdi, a former bodyguard of his, to the status of “royal noble consort” — a practice last exercised a century ago. Months later he summarily stripped her of her rank and titles; a royal statement claimed that she had been disloyal and had tried to compete with Queen Suthida Vajiralongkorn Na Ayudhya, the king’s wife. Ms. Sineenat disappeared from public view, sparking rumors that she had been imprisoned or even killed. Then in September the king ordered her privileges reinstated, now calling her “flawless.”

By my count, based on announcements in the royal gazette, more than 200 people have been dismissed, demoted or imprisoned since 2016, without access to proper legal process, presumably on the personal orders of the king.

The country’s punishing lèse-majesté laws were not applied in recent years, at the king’s request. But with the protests of the past months becoming more and more daring, the government has redeployed them recently.

It is not the first time the royal family’s prerogatives have been in tension with the popular will. But protesters see King Maha Vajiralongkorn’s personalized exercise of power as a breach of the monarchy’s tacit social contract with the Thai people.

Pavin Chachavalpongpun is an associate professor at Kyoto University’s Center for Southeast Asian Studies.