Wan Muhamad Noor Matha (PCC) Pichet Chuamuangphan (PTP) Paradorn Prissanananthakul (BTP) Natthaphong Ruengpanyawut (PP)

[31] Seni Pramoj's wife told the US chargé d'affaires that Pridi had the king assassinated, and Democrat Party members spread the same rumor to the British Embassy.

[33] By the time of the elections of August 1946, the Democrat Party was backed by royalists like Prince Upalisarn Jubala, Srivisarn Vacha, Sridhamadibes, Borirak Vejjakarn, and Srisena Sombatsiri.

On 29 November 1951, the military and the police seized power, just as King Bhumibol's ship was returning to Thai waters.

Unlike Marshal Plaek, Sarit deified the throne, thus removing any advantage that the Democrats, who had previously been dominated by royalists, may have had.

Eight months later, he recovered, returned and led another coup while dissolving parliament, abrogating the constitution, and ruling by revolutionary council.

Thanom Kittikachorn, who had succeeded Sarit after his death, was pressured to promulgate a democratic constitution on 20 June 1968, and hold elections in February 1969.

A violent crackdown and subsequent intervention by the king led to the appointment of Privy Councilor Sanya Dhammasakdi as premier.

The king and queen returned from a trip to the south and visited monk Thanom, leading Seni to resign from the premiership in protest.

The Democrat Party, being led by Bhichai Rattakul, became an outspoken opponent of military rule in Thai politics during the 1990s.

In the 1990s, under the leadership of Chuan Leekpai, a native of Trang Province, the Democrats quickly became the dominant party in southern Thailand.

The first Chuan government (1992–1995) fell when members of the cabinet were implicated in profiting from the Sor Phor Kor 4-01 land project documents distributed in Phuket Province.

In the election campaign, the Democrats had a populist platform, promoting job creation, universal education and health care, and law and order against crime and corruption.

The TRT championed populist policies with its focus on providing affordable and quality health care for all citizens, village-managed microcredit development funds, the government-sponsored One Tambon One Product program, and others.

The populist policies earned the TRT enormous support from rural constituencies, unprecedented in Thailand's history.

Opposition to the TRT government rose in Bangkok after Thaksin's family announced their tax-free sale of their 49.6 percent stake in Shin Corp to Temasek for almost 73.3 billion baht on 23 January 2006.

Several Democrat Party leaders also joined the PAD,[44] which accused Thaksin of disloyalty to the throne and asked King Bhumibol to appoint a replacement prime minister.

On 24 March 2006, Abhisit Vejjajiva publicly backed the People's Alliance for Democracy's call for a royally-appointed government.

[45] Abhisit and his opposition parties allies boycotted the April 2006 elections, claiming it "diverted public attention" from Thaksin's corruption charges and his sale of Shin Corp.[46] The boycott caused a constitutional crisis, prompting Thaksin to call another round of elections in October 2006, which the Democrats did not boycott.

Abhisit voiced displeasure at the 2006 coup that overthrew Thaksin, but otherwise did not protest it or the military junta that ruled Thailand for over a year.

Despite being banned from politics for five years, Thaksin Shinawatra was popular in his former support bases in the central, north, and northeastern regions and attempted to maintain an active role in Thai politics by supporting the People's Power Party, which had become the successor party of the banned TRT.

He claimed that while his platform was categorically considered to be populist, it sought to curb inflation while maintaining fiscal soundness, to apply the village-based microcredit development funds used in the Thaksin-led government, but do it as part of promoting royalist sufficiency economy policies in rural areas, and to strengthen the country's long-term competitiveness through universal education through high school.

In the junta-administered 2007 parliamentary election, the People's Power Party won the largest share of the vote and formed a six-party coalition government.

During the critical period that followed the rulings, it is alleged that army commander and co-leader of the 2006 coup, General Anupong Paochinda, coerced former PPP MPs, mainly those of the Friends of Newin Group, to endorse a Democrat Party-led coalition, which secured enough parliamentary votes to allow Abhisit to be elected prime minister.

[50][51] During Songkran (Thai New Year), anti-government UDD protesters disrupted the Fourth East Asia Summit.

[57] At the general election on 3 July 2011, the Democrats were only able to defend 159 seats in the House of Representatives, while rivaling Pheu Thai Party led by Yingluck Shinawatra won an outright majority.

[66] At the first meeting of the new parliament, Democrat ex-prime minister Chuan was nominated speaker of the House of Representatives by PPRP deputy leader Nataphol Teepsuwan and was elected to that office.

[69] Prinn Panitchpakdi, deputy leader of the Democrat Party was accused of many sexual misconduct cases, including rape.

[74][75] During the 2nd prime ministership election, 16 out of 25 Democrat MPs voted for the Pheu Thai candidate Srettha Thavisin despite agreeing to abstain.

On 9 December 2023, a meeting was held to choose the party’s new leader with four candidates running for leadership — former prime minister Abhisit Vejjajiva, the party’s acting leader Chalermchai Sri-on, former Democrat MP Lt-Colonel Thita Rangsitpol Manitkul [76] former MP and businesswoman Watanya “Madame Dear” Bunnag.