Washington (CNN) Millennials could be one of the biggest political forces in America today, if they wanted.

Defined by Pew as those born between 1981 to 1996, millennials make up about 22% of the US population, and at some point between November's midterms and the 2020 election, they're expected to surpass baby boomers as America's largest living generation. They're a massive voting bloc, capable of setting policy priorities and swinging elections.

They're also grossly underrepresented in American politics.

In Congress, there are currently only eight millennials in the House and none in the Senate, according to Quorum , a public affairs software company. And millennials' vote at lower rates than older generations. In 2016, just more than half of eligible millennials voted. In 2014, less than a quarter voted.

"Our generation is at the beginning of becoming legislators in this country," said Steven Olikara, founder of the nonpartisan group Millennial Action Project.

Olikara believes millennials are capable of transforming politics. They are "highly idealistic young people," he said, and their political rise coincides with "our country's worsening polarization and political dysfunction."

A sharing generation

Millennials are drawn into politics over issues that affect them, like student debt, the economy, the environment, and health care, said Erin Loos Cutraro founder of She Should Run, a nonpartisan group that helps women run for office.

"Millennials especially want to put their time toward something they know they can change," she said.

Cutraro called millennials a "sharing generation" and said their comfort with social media could reshape politics, showing voters a different side of campaigning and lawmaking.

"It really flies in the face of conventional wisdom in politics, which is: be scripted, get it right, go back to the same few talking points," she said. "Now we have a generation who -- not all, but some -- are tearing down those walls and saying, 'This is what it looks like to run for office,' and I think that that overall authenticity and transparency only stands to benefit politics."

That millennial attitude showed up in an Instagram post Wednesday by Alexandria Ocasio-Cortez, who was photographed for Vanity Fair. In the caption for the photo, she sounded more like a social media influencer than a typical politician, writing that she felt anxious and overwhelmed by her sudden fame after winning her New York primary.

"Every time a media event like this happens I get NERVOUS," she wrote. "But I also think about how I never got to see anyone like me on any magazines growing up."

Getting millennial voters' attention could take a lot more than traditional campaign approaches.

"Millennials have a unique perspective in that they've grown up in what's essentially an attention economy," said Scott Starrett, co-founder of the design firm Tandem. "So the idea of what gets your attention and why has never been more prevalent."

Tandem worked on design for Ocasio-Cortez's campaign, which broke out of cliched campaign design tropes and used a distinct color scheme and design elements. Starrett thinks millennials could see other uncommon visual approaches.

"I think because they are natives to a much richer visual culture, they are more familiar with the relevance of visual culture," he said.

Politically independent

The first millennials became constitutionally old enough to run for the US House in 2006, when they turned 25. Former Rep. Aaron Schock, known, fittingly, for his Instagram account before he resigned in 2015, was the first millennial on Capitol Hill when he was sworn in in 2009. By 2031, every millennial will be 35 or older, old enough to run for president.

But generational turnover in Congress can be slow, with incumbent advantage keeping lawmakers in office year after year. Today, the average American is 20 years younger than their representative in Congress, Quorum data found.

A number of candidates running in this year's midterms might be able to lower the average age of Congress. Millennial midterm candidates include Iowa state lawmaker Abby Finkenauer, Ohio county clerk Aftab Pureval, and former Obama administration staffers Ammar Campa-Najjar of California and Lauren Underwood of Illinois.

Though millennials' experience varies widely by demographics, geography, and politics, they're a generation shaped by experiences like the Great Recession, high levels of student debt, and the rise of social media.

They are the most racially diverse generation and the most likely to live in metro areas. They're more likely to be unmoored from social institutions -- the most likely to be religiously unaffiliated and the least likely to be married. They're the least trusting of others. They're the most likely to live with their parents and not be in the workforce. They've been mocked in the culture for being given participation trophies they never asked for, and many feel as if they're inheriting a mess they didn't make.

A recent political ad for an anti-Trump "Knock The Vote" campaign played at generational discord, pitting older voters, or a generation of "doers," against a younger generation of "whiners."

"You'll like some meme on Instagram," one says. "You might even share this video on Facebook," says another.

Politically, millennials are the most independent generation . They're the least likely to see big differences between the Democratic and Republican parties, and a March Pew poll found 44% of millennials identify as independent, while 35% identify as Democrats and 17% as Republican.

Millennials are "rejecting the old partisan boxes, they're rejecting the old binary choices," Olikara, of the Millennial Action Project, said.

Once derided for their hashtag "slacktivism," movements powered in large part by millennials on social media have directed political action and activism towards causes like #LoveWins, #BlackLivesMatter and #MeToo. It's perhaps an omen of what's to come.

Once millennials become a majority in Congress, Olikara said, "I think it's very likely that partisan identity will not be the driving force in American politics." Instead, he hopes, politics will be "more issue focused."

"We have a huge opportunity," he said.