In early February, another, smaller, Thaksin-linked party, Thai Raksa Chart, nominated the king’s older sister, Ubolratana Rajakanya Sirivadhana Varnavadi, as its candidate for prime minister. A firestorm of speculation erupted on social media about why and at whose urging — until King Maha Vajiralongkorn Bodindradebayavarangkun declared that any royal involvement in politics was inappropriate. Ms. Ubolratana promptly withdrew her candidacy and Thai Raksa Chart was dissolved — a turn of events that weakened Pheu Thai, which had joined forces with Thai Raksa Chart and agreed not to compete with it in some constituencies.

Mr. Thaksin hit back with an astonishing piece of showmanship. Just two days before the election, he hosted in Hong Kong a ritzy wedding party for his youngest daughter that featured Ms. Ubolratana as guest of honor. Photos showing Mr. Thaksin and Ms. Ubolratana together promptly circulated online.

The following night — the eve of the election — King Vajiralongkorn issued another royal statement. Quoting his late father, King Bhumibol Adulyadej, he urged Thais to select “good people” to rule Thailand, in the name of “harmony, national security and the people’s happiness.” The message was widely interpreted as a rebuke of Mr. Thaksin and an implicit call to endorse parties aligned with the junta.

A hashtag that translates as “We are grown-up now and can choose for ourselves” soon went viral. The establishment had chastised the young, and now the young were pushing back against paternalism. On the morning of the election, in Ubon Ratchathani, a midsize city in the northeast, a first-time voter told me, grinning, that he did indeed plan to vote for “someone good” — meaning, Mr. Thanathorn .

The face of Thailand’s next government is likely to remain unclear for a while. On Wednesday, seven pro-democracy parties, including Pheu Thai and Future Forward, announced that since the “democratic front” they form had won a majority of the lower house, it should get to select Thailand’s next leader. (The prime minister is chosen by a majority vote of the full Legislature, with includes the 500 elected members of the House of Representatives and 250 military-appointed senators.)

The election commission released partial results on Thursday, but only for 350 of the 500 seats contested; the remaining 150 are to be allocated according to a complicated formula based on each party’s showing overall. No final, complete results are expected until after King Vajiralongkorn’s coronation in early May.

More legal challenges could soon engulf the pro-democracy parties. The police have accused Mr. Thanathorn, and two of his colleagues at Future Forward, of “spreading false information online” — a charge that carries a sentence of up to five years in prison. A lawsuit could endanger his entire party.

But whatever happens next to Future Forward, its showing in this week’s election was remarkable. And that performance has laid bare yet another fracture in an already very divided political scene: a major generation gap. Any attempt by the establishment to suppress the youthful idealism of Thailand’s new voters could be a dangerous miscalculation.

Duncan McCargo is a professor of political science at the University of Leeds and a visiting professor at Columbia University.

The Times is committed to publishing a diversity of letters to the editor. We’d like to hear what you think about this or any of our articles. Here are some tips. And here’s our email: letters@nytimes.com.

Follow The New York Times Opinion section on Facebook, Twitter (@NYTopinion) and Instagram.