Each party or coalition, by law, had to register and announce whether it supported or disapproved of the proposed amendment; this was announced in the short gazette that was distributed along with the poll card. Since this assertion was binding on the members elected, the election was de facto a referendum on the proposed amendments. Only the Kuomintang, the governing DPP, and the three minor party registered their support for the amendments; the others have announced objection. Notably, the political tendencies dubbed pan-green and pan-blue coalitions were each split down the middle in their opinions on the proposed amendments, with the dominant partner in each coalition supporting the amendments, probably because the proposed electoral system would benefit large parties.
Each individual in the electorate voted for one from the 10 parties and 2 coalitions. The seats were distributed amongst the parties and coalitions based on the total number of votes garnered by each. There was to be at least 1 female member guaranteed for every 4 elected in each party/coalition; and 1 aboriginal member guaranteed for every 30 in each party/coalition.
The elections themselves generated very little interest in Taiwan, which accounted for the record-low turnout. Polls indicated that most Taiwanese did not plan to vote and had little interest in or knowledge of what the election is about. In addition, most parties did not spend very much in campaign funds. Terrible weather in the north of Taiwan on election day also affected the turnout.
The only authority of the National Assembly was to accept or reject amendments which were proposed almost unanimously by the Legislative Yuan in August 2004, one of which was to abolish the National Assembly.
The proposed amendments may be summarized as follows:
Using referendums to ratify constitutional amendments has been portrayed by some as a step toward Taiwan independence. However, the requirement that such a referendum must first be approved by a three-fourths vote of the Legislative Yuan, and that at least 50% of the whole electorate had to vote for the change for the referendum to succeed considerably reducing the chance that these amendments would trigger a conflict with the People's Republic of China.
One question which was unresolved until after the elections was the threshold for passage of the amendments. The DPP and KMT had advocated a majority vote for passage, while the smaller parties advocated a three-fourths threshold. It wasn't until the week after the election that the Legislature agreed on the three-quarters voting threshold - when it was already clear that the parties which supported the amendments controlled more than 75% of the National Assembly. Also, the TSU has advocated voting on the amendments separately, which was impossible as the inter-party agreement for these amendments stipulated that they be adopted all or none.
The proposed system of electing Legislative Yuan members is unfavorable to smaller parties, but was originally supported by the two smaller parties in Taiwan for different reasons.
This election initially generated little interest, as it was largely a procedural formality to elect a new National Assembly whose sole purpose would be to deal with the amendments, which were passed almost unanimously by the Legislative Yuan in August 2004. However, the unexpected pan-blue coalition victory in the December 2004 legislative election considerably changed the electoral landscape.
Originally, the Taiwan Solidarity Union supported the constitutional amendments on the belief that they would be a prelude to a more thorough move toward Taiwan independence. The Constitutional amendments were part of a package originally promoted by the Democratic Progressive Party, but were passed almost unanimously after compromises were made on the wording. However, after the December elections, which returned a pan-blue majority opposed to a rapid move toward independence, the TSU reconsidered its support, and has announced its opposition to the amendments.
Similarly, the People First Party changed its position. Most analysts believe that PFP leader James Soong had initially planned to have a major role in a reformed KMT which would consist of a merger of the KMT and PFP. However, the PFP performed poorly in the December elections, and after the elections Soong ended any talk of a merger and began an effort to improve relations with the DPP. The reconsideration of support is widely believed to be because the reforms would hurt small parties such as the PFP.
Following the visit by Kuomintang leader Lien Chan to mainland China and a similar trip by PFP leader James Soong, the election has been unexpectedly turned into a referendum on pan-blue and pan-green plans for relations with the People's Republic of China. During the week before the election, President Chen Shui-bian gave a television interview in which he argued that a vote against the constitutional amendments would play into the hands of the PRC and that the amendments marked a step toward legal Taiwan independence. However, these arguments have were widely criticized in Taiwan, since the Kuomintang, which is anti-Taiwan independence strongly supported the amendments, while the pro-independence Taiwan Solidarity Union strongly opposed them.