Democratic Progressive Party (DPP) presidential candidate Frank Hsieh's (
The result was a dramatic turn around as Su had voluntarily withdrawn from a contest with former vice premier Yeh Chu-lan (葉菊蘭), who had expressed her interest in running as Hsieh's vice presidential candidate.
Late last month he took what he described as a long "journey of learning" to the US.
Su's departure resulted in speculation from a number of media outlets, including the Chinese-language Liberty Times (the Taipei Times' sister newspaper), that Hsieh would be forced to choose Yeh due to the lack of any alternative.
The speculation arose partly because choosing Yeh could also help to secure votes from the Hakka community of which Yeh is a member.
But the situation took a dramatic turn after Hsieh called a unexpected press conference during his visit to Singapore on Aug. 12.
It was here that he revealed for the first time that he had invited Su to work with him.
The unity between the two DPP heavyweight candidates guarantees that next year's presidential race will be a battle between the DPP's Hsieh-Su ticket and the Chinese Nationalist Party's (KMT) presidential candidate Ma Ying-jeou (馬英九) and his running mate Vincent Siew (蕭萬長).
Chen Chao-jian (
This is partly because cooperation between Hsieh and Su may be able to help the former overcome regional preferences.
Hsieh attracts more support from the DPP's traditional stronghold of southern Taiwan, but his partnership with Su may allow him to carve himself a niche in the north, which is a Su stronghold, Chen said.
Choosing Su also helps Hsieh carry out the wishes of President Chen Shui-bian (陳水扁), who had shown a preference for a Hsieh-Su ticket.
Chen helped Hsieh keep his promise that the two contenders who garnered the most votes in the primary should pair up, Chen Chao-jian said.
"Having Su as his running mate helps Hsieh restore the DPP's faction balance that was upset during the DPP primary," Chen Chao-jian said.
The professor was referring to fierce bickering between the Hsieh and Su camps during the primary.
At the time Su's camp labelled Hsieh as "sly" and questioned his integrity because of his involvement in several judicial cases.
Hsieh's camp countered by attacking Su for being close to the party's former New Tide faction.
Several members of the faction were boycotted by DPP grassroots supporters in the party's legislative primary for their outspokenness against the party.
"If Hsieh had chosen Yeh, he would have inevitably suffered a relationship rupture with the DPP's [former] New Tide faction," Chen Chao-jian said.
Chiou Chang-tay (丘昌泰), chairman of the National Central University's Graduate Institute of Hakka Politics and Economics told the Taipei Times that Hsieh's continuous emphasis of Su, Yeh and himself as a team sharing a common goal had helped to minimize Hakka pessimism about the the Hsieh-Su ticket.
After Hsieh formally announced that Su would be his running mate last Wednesday, he also invited Yeh to be his campaign manager, calling himself, Su and Yeh a "golden triangle."