Rep. Cho Kyoung-tae, a third-term lawmaker representing Saha-gu in Busan, was once portrayed as a pioneer in condemning localism in politics, as he survived three consecutive elections in the traditionally conservative constituency.

But after 12 years as an opposition representative, Cho decided to defect to the ruling party ahead of the upcoming general election, arousing derision and accusations that he had betrayed his political beliefs for the sake of reelection.

“I hope that my fresh start acts as a positive stimulant to both ruling and opposition parties,” he told reporters Thursday, after submitting his application to join the Saenuri Party.

Kim Moo-sung, Saenuri’s party chief and a fifth-termer in Busan, welcomed Cho’s arrival with open arms.

“Rep. Cho’s thoughts have always been largely in tune with that of our party,” Kim said, introducing the former opposition member to the party’s supreme council meeting.

The lawmaker defected from The Minjoo Party of Korea on Tuesday, claiming that the opposition camp was trapped in a hegemonic frame, refusing to communicate with others.

The Minjoo Party took his departure with composure, as the lawmaker had long been at odds with party chief Moon Jae-in and had recently been displaying friendly gestures toward the ruling party and the Park Geun-hye administration.

“We are not at all affected (by Cho’s defection) as he made no contribution whatever as a party member,” said the Minjoo Party’s Busan office through a statement.

The party headquarters also remained unfazed by Cho’s change of affiliation and focused more on welcoming influential new figures such as Dumun Political Strategy Institute director Lee Cheol-hee.

Despite the apparent indifference, however, the opposition party is facing the risk of losing Busan altogether to the ruling camp in the upcoming parliamentary elections.

With Cho off the list, the only remaining Minjoo lawmaker in Busan is party chief Moon, who had earlier pledged not to run.

The southeastern city, in addition to being the nation’s second-largest, is an area over which the opposition party has been striving to loosen the conservative party’s grip.

It also happens to be the hometown of all three of the top potential presidential candidates -- Saenuri chief Kim, Minjoo Party chief Moon, and head of the forthcoming People’s Party Rep. Ahn Cheol-soo.

The presence of opposition member Cho in this conservative-dominated city had not only acted as a Maginot Line against the ruling party’s expanding clout, but also symbolized the opposition party’s challenge against incumbent powers.

Rep. Cho, on the other hand, is likely to have his political integrity called into question after changing sides.

“I entered politics to fulfill the late President Roh Moo-hyun’s dream to eradicate localism,” Cho had said back in 2012, at the party’s primary race for presidential candidacy.

The former policy adviser to the late president had also repeatedly criticized President Park Geun-hye for a lack of communication, at least before his recent change of heart.

“What good will it be for the party to bring somebody, lawmaker or not, who will not even be missed by his own former party,” said Seok Dong-hyun, Saenuri‘s preliminary candidate in Busan’s Saha-B constituency, which Cho currently represents.

By Bae Hyun-jung (tellme@heraldcorp.com)