This article originally appeared in Forbes.

As voters in five states head to the polls today, much of the focus will be on the Republican presidential contenders, and whether anyone can create a roadblock on businessman Donald Trump’s pathway to the nomination. But a similar drama is unfolding in the Democratic primary.

Like Trump, Senator Bernie Sanders is a populist candidate appealing to an overlooked constituency. While once considered a weak candidate, Sanders now threatens former Secretary of State Hillary Clinton’s long-anticipated quick coronation as the Democratic nominee. Where Sanders stands after this week depends on one of the key story-lines of the Democratic primary so far, and whether it continues during the contests this week.

In the first contest, Sanders won 84% of voters ages 17 to 29 in Iowa, according to entrance polls. This kicked off a trend. In New Hampshire, Sanders won 83% of 18 to 29 year-olds. Most recently, in Michigan, in his upset victory, Sanders won 81% of 18 to 29 year-olds. As Sanders might say, that gap is YUGE.

While Clinton is the Democratic frontrunner, a long primary does not benefit her. She has already struggled during debates when faced with attacks from the left. Today, in what has been nicknamed, “Super Tuesday II,” Sanders and Clinton are competing in Florida, Illinois, Missouri, North Carolina and Ohio for delegates.

For the first time, 17-year-olds can vote in the Ohio primary as long as they turn 18 by the general election. This is already legal in Iowa. In January, Politico ran a story on Sanders’ strategy in Iowa to target younger youth voters, including 17-year-olds. One advantage of targeting 17-year-olds as compared to 18 or 19 year-olds is that gaining supporters before they get to college means those supporters are more likely to be in caucuses spread across the state of Iowa and winning multiple caucuses mattered. The Sanders campaign targeted young voters in a sophisticated manner:

They’re taking advantage of the thinly sliced market segments offered by digital powerhouses like YouTube, Snapchat and Facebook , which sell the ability to send ads very specifically to the phones of, say, Iowans in their late teens. Over on Pandora , youth-oriented Bernie commercials can be made to interrupt only pop music shuffles for the kinds of songs their parents would never be able to identify, from heavy metal rock bands like Five Finger Death Punch to hip hoppers Twenty One Pilots and electropop star Halsey.

Then there’s the free stuff. Sanders is giving away T-shirts and key chains to 17-year-olds who agree to be part of his social media network, exchange text messages with his campaign and start pro-Bernie chapters in their high schools. More than 1,000 “FEEL THE BERN” keychains have already been shipped out, his campaign said. In return, the Sanders campaign gets some pretty valuable pieces of data from its supporters that it might not otherwise have because they’re minors, including names, addresses, cell phone numbers and where exactly they are eligible to caucus.

Following his recent win in Michigan, Sanders can reassert that his candidacy is viable with a strong showing in the Ohio primary, 17-year-olds and all. If young voters in the Buckeye State and beyond continue to “Feel the Bern,” the Democratic primary may continue over the next few months, much to Clinton’s chagrin.