South Koreans voted Tuesday for a new president, with victory widely predicted for a liberal candidate who has pledged to improve ties with North Korea, re-examine a contentious U.S. missile defense shield and push sweeping economic changes. Conservatives worry that a victory by Moon Jae-in might benefit North Korea and put South Korea at odds with its most important ally, the United States. Moon has been the clear favorite as the country's powerful conservative forces struggle to regroup after a huge corruption scandal that led to President Park Geun-hye's removal from office and arrest in March. "I gave all my body and soul (to the election) to the very end. Me and my party invested all our efforts with a sense of desperation, but we also felt a great desire by people to build a country we can be proud of again," Moon, 64, told reporters after casting his ballot. The final opinion surveys released last week showed Moon, the Democratic Party candidate, had about a 20 percentage point lead over his two main rivals â€" a centrist and a conservative. His victory would end a near decade of conservative rule by Park and her predecessor, Lee Myung-bak. When the liberals were last in charge in Seoul, Moon served as chief of staff for then President Roh Moo-hyun. They sought closer ties with North Korea by setting up large-scale aid shipments to the North and by working on now-stalled joint economic projects. Voting stations opened at 6 a.m. and are set to close at 8 p.m. South Korean TV stations plan to release the results of their joint exit polls soon after the vote ends and are expected to predict a winner before midnight. The winning candidate will be officially sworn in as South Korea's new president after the National Election Commission ends the vote count and confirms the winner on Wednesday. This forgoes the usual two-month transition because Tuesday's vote is a by-election to choose a successor to Park. Her term was originally to end in February 2018. The new leader will still serve out a full, single five-year term. Some voters were eager to see an end to a decade-long rule of conservative governments in Seoul they feel failed the economy and undermined the country's democracy before the corruption scandal toppled Park.