Who Voted in 2016? Millennials Will Outnumber Boomers at the Ballot Box

Barack Obama
U.S. President Barack Obama speaks to an overflow crowd outside a rally in support of Hillary Clinton's campaign, in Las Vegas on October 23. Demographic changes could pose particular problems for the Republican Party. Kevin Lamarque/File Photo/Reuters

Baby boomers vs. millennials: It's the battle that has defined our decade. How much should you spend on avocados? Who caused climate change? Which side is the bigger bunch of snowflakes? The generational battlegrounds are endless.

In the political sphere, it's only a matter of time before the baby boomers lose their long-held advantage, according to a new study. "The influence and clout of the baby boomers is waning, and millennials are rising," Pew Research Center economist Richard Fry told The Hill, in an interview to promote a paper that outlines the changing demographics of U.S. politics.

Millennials and Generation X, the two younger generations of voters, together cast almost 70 million votes in the 2016 election. That means they outvoted the baby boomers and the so-called silent generation, who came of age shortly after World War II, the two of which together cast about 68 million votes.

Baby boomers still make up the largest segment of the electorate—35 percent, or 48.1 million votes in 2016—but their numbers peaked at 50.1 million votes in 2004 and are now in decline, while the millennials are only set to expand, the research says.

Millennials especially have the potential to boost their political clout by turning out in greater numbers. Just 49 percent of eligible voters from that generation voted in 2016, compared with 69 percent of eligible baby boomers.

"The millennial population and the millennial electorate, they're going to continue to grow in size. So far, their turnout hasn't really materialized," Fry told The Hill. "We would expect their turnout to increase more as they mature."

The rising power of younger generations could pose problems in the long term for the Republican Party.

A Pew study from May found that almost a quarter of Republican supporters under the age of 29 defected to the Democrats over the course of the 2016 election campaign. At one stage, 44 percent of Republicans under 29 had abandoned the party, but just under half of those ultimately returned. It's not clear from the research the extent to which Donald Trump's candidacy was to blame for this.