power on military power. During this time, Chiang ruled more as a dictator than as a leader of a one-party state. He used white terror tactics and various military campaigns to destroy the CCP, and the police and military apparatus were freely used to attack dissenters. However, Chiang's influence never extended beyond the Yangtze Delta, and the rest of the country was under the effective control of former warlords, and Chiang faced insurrections from them throughout the 1930s, even after the Northern Expedition, which had nominally unified the country. Regional political power remained strong throughout Republican China, and central authority deteriorated continuously until the Second Sino-Japanese War, to the point that Chiang became no more than the "head of a loose coalition," as observed by Albert Wedemeyer. Republic of China on Taiwan since 1949 After the death of Chiang Kai-shek in 1975, Vice President Yen Chia-kan briefly took over from 1975 to 1978, according to the Constitution, but the actual power was in the hands of Premier Chiang Ching-kuo (), who was KMT chairman and a son of Chang Kai-shek. During the presidency of Chiang Ching-kuo from 1978 to 1988, Taiwan's political system began to undergo gradual liberalization. After the lifting of martial law, the opposition Democratic Progressive Party (民主進步黨) was formed and allowed to participate overtly in politics. After Chiang Ching-kuo died in 1988, Vice President Lee Teng-hui (李登輝) succeeded him as the first Taiwan-born president and chairman of the KMT. Lee became the first ROC president elected by popular vote in 1996, despite the PRC's missile tests. In 2000, Chen Shui-bian (陳水扁) of the pro-independence Democratic Progressive Party (DPP) was elected president, marking the first peaceful democratic transition of power to an opposition party in ROC history and a decisive end to the KMT's monopoly in administration of the central government. In the 2004 presidential election, the day after being shot while campaigning, Chen was reelected by a narrow margin of 0.2%. The KMT filed lawsuits to demand a recount, alleged voting fraud and staged huge rallies to demand a new election. The courts ruled that the election was accurate and valid. In both of Chen's terms, the DPP and the independence-leaning Pan-Green Coalition failed to secure a majority in the legislature, losing to the KMT and the pro-unification leaning Pan-Blue Coalition. This has led to many impasses; the president in the ROC system does not have the