South Koreans voted Tuesday in a presidential election a conservative candidate declared a "war of regime choices" in stark contrast to the liberal front-runner looking to overturn a decade of right-leaning rule.
The vote was the culmination of a frenzied two-month race set up by the scandal that ousted Park-Geun-hye, now jailed while awaiting trial on corruption charges.
Conservatives worry that a victory by the liberal, Moon Jae-in, might benefit North Korea and estrange South Korea and its most important ally, the United States. Moon was the clear favorite as conservative forces worked to regroup Park's devastating scandal.
"I gave all my body and soul (to the election) to the very end," 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 — a centrist and a conservative.
Moon was chief of staff for the last liberal president, the late Roh Moo-hyun, who 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.
Outspoken conservative Hong Joon-pyo, the candidate from Park's Liberty Korea Party, described the election as a war between ideologies and questioned Moon's patriotism.
After voting, Hong said the election was a "war of regime choices between people, whether they decide to accept a North Korea-sympathizing leftist government or a government that can protect the liberty of the Republic of Korea," South Korea's formal name.
Hong has pitched himself as a "strongman" who can hold his own against other "nationalist" leaders in Washington, Tokyo and Beijing. He also calls for the United States to bring back tactical nuclear weapons to South Korea after withdrawing them in the 1990s.
The polls have shown Hong and the centrist Ahn Cheol-soo running even.
Voting stations are set to close at 8 p.m. and South Korean TV stations plan to release the results of their joint exit polls soon after the vote ends. They are expected to predict a winner before midnight.
The National Election Commission said more than 55 percent of the country's 42.4 million eligible voters cast their ballots as of 1 p.m., a measurement that included the 11 million people who participated in early voting last week.
The winner will be sworn in after the National Election Commission confirms the result Wednesday. Because the vote is a special election, the new president will forgo the usual two-month transition and will serve one full, five-year term rather than only completing Park's original term, which was to end in February 2018.
Some voters were eager to end the long conservative rule, which they think failed the economy and undermined democracy before Park's corruption scandal.
"Moon wasn't my favorite candidate in terms of policies, but I voted for him because he represented the best chance to switch government power, and that's the most important thing," said Lee Ah-ram, a 39-year-old Seoul resident. "We need a leader who can restore the people's trust in government that was damaged by Park's scandal."
Others were more worried about the growing North Korean nuclear threat and fears that Seoul was losing its voice in international efforts to deal with its belligerent rival.
"We need a leader who can protect national interests and hold his ground against the surrounding global powers of the United States, China and Japan," said Kim Hyeong-seok, a 67-year-old who said he voted for Hong. "This is not the time to keep our eyes just on domestic issues — we need to think about the nation's long-term future and peace."
Park's trial later this month on bribery, extortion and other corruption charges, could send her to jail for life if she is convicted.
The allegations incensed many in South Korea, with millions taking to the streets in protest. Park sympathizers later staged their own rallies. Dozens of high-profile figures, including Park's longtime confidante, Choi Soon-sil, and Samsung's de facto leader, Lee Jae-yong, have been indicted along with Park.
Moon frequently appeared at anti-Park rallies and the corruption scandal boosted his push to re-establish liberal rule. He called for reforms to clean up social inequalities, excessive presidential power and corrupt ties between politicians and business leaders. Many of those legacies dated to the dictatorship of Park's father, Park Chung-hee, whose 18-year rule was marked by both rapid economic rise and severe civil rights abuse.
As a former pro-democracy student activist, Moon was jailed for months in the 1970s while protesting against the senior Park.
Moon has called Park Geun-hye's hard-line North Korea policy a failure. If elected he says he'll employ both pressure and dialogue to persuade the North to abandon its nuclear ambitions. He also advocates building up a more assertive South Korea.
Following a standoff between President Donald Trump and North Korean dictator Kim Jong Un over Kim's vow to advance his country's nuclear weapons programs, Moon has talked more about bolstering national defense in what analysts see as an attempt to woo conservative voters.
Many analysts say Moon, if elected, likely won't pursue drastic rapprochement policies because North Korea's nuclear program has progressed significantly since he was in the Roh government a decade ago.
A big challenge for whoever wins will be Trump, who has proven himself unconventional in his approach to North Korea, swinging between intense pressure and threats and offers to talk.
"South Koreans are more concerned that Trump, rather than North Korean leader Kim Jong Un, will make a rash military move, because of his outrageous tweets, threats of force and unpredictability," Duyeon Kim, a visiting fellow at the Korean Peninsula Future Forum in Seoul, wrote recently in Foreign Affairs magazine.
"It is crucial that Trump and the next South Korean president strike up instant, positive chemistry in their first meeting to help work through any bilateral differences and together deal with the North Korean challenge."
AP writer Foster Klug contributed to this report.