One striking aspect of the Dec. 19 presidential election was the extraordinarily high voter turnout among people in their 50s. According to the exit polls conducted jointly by the three nationwide TV broadcasters, a whopping 89.9 percent of the voters aged 50-59 cast ballots.

The figure stands out when compared with the average turnout of 75.8 percent or the turnouts of other age groups ― 65.2 percent for those in their 20s, 72.5 percent for 30-somethings, 78.7 percent for the 40-49 year-olds and 78.8 percent for those aged 60 and over.

Before the election, pundits suggested that people in their 40s would hold the key to the 18th presidential vote as they were seen as a generation with a liberal heart and a conservative mind. On top of that, they accounted for the largest share of the electorate ― 21.8 percent.

Yet in this election, the 50-59 year-olds eclipsed the 40-somethings with their surprisingly high turnout.

The total number of Koreans in their 50s amounts to 7.78 million, accounting for 19.2 percent of the entire 40.46 million electorate. Of them, some 6.9 million people went to the polls, with 62.5 percent or 4.3 million voting for Park Geun-hye of the ruling conservative Saenuri Party, and 37.4 percent or 2.6 million voting for Moon Jae-in of the main opposition Democratic United Party.

What drove so many 50-somethings to the polls? One theory points to the DUP’s focus on the voters in their 20s and 30s, which led aged people to feel that they were being pushed to the margins. So they went to the polls in droves to make their presence felt through voting.

Another theory notes that people in their 50s are mostly baby boomers who were born between 1955 and 1963. As these people have recently retired or are facing retirement from their main career jobs, they are feeling insecure economically. So they went to the polls massively to vote for a candidate who promised to take better care of them.

Analysts also note these people are worried about the threats to national security posed by North Korea. Hence the weak support for Moon who promised to follow a policy of appeasement toward the North.

One lesson this election offers to the two parties is that they have to take into account demographic changes when they forge strategies for next elections.

Ten years ago, the number of the 50-somethings was 4.54 million. Due to rapid population aging, the figure increased 70 percent in a decade. The pool of aged voters will further expand going forward. A political party can ignore demographic changes only at its own peril.