WASHINGTON -- Hillary Clinton stopped in at a fast-food restaurant on her first official day of campaigning and got some bad news, to go. The staff at the Chipotle in Maumee, Ohio, gave Clinton a chicken burrito bowl and an iced tea, but nothing else: no squeals of recognition, no handshakes, no earnest questions about the future of the country. The Democratic presidential candidate is one of the most famous people on Earth, yet nobody there recognized her.

And thus began the courting of "Chipotle voters" -- young adults who turned out in record numbers in 2012 and 2008 and are the target of presidential candidates from both major parties. Republican Sens. Rand Paul of Kentucky and Marco Rubio of Florida made stops at the same Mexican fast-food joint. Even Sen. Ted Cruz of Texas cracked a Chipotle joke at a campaign event last weekend.

The particular allure for being seen at Chipotle is tying yourself to its “fresh” and “less processed” offerings -- which are popular with young adults, a Morgan Stanley consumer survey found. With its burritos and bowls, Chipotle is the "unequivocal favorite among millennials," Morgan Stanley found. "Chipotle is perceived as the brand of today," John Gordon, of the Pacific Management Consulting Group, told CNN.  

Wooing Millennials

That is the type of branding every candidate wants to tap into. The challenge will be one that has plagued every candidate since 1971, when 18-to-20-year-olds were granted the right to vote: How do you appear aware of their issues and in touch with their concerns?

Clinton must be the favorite of millennials in order to win the White House. Along with women and minorities, young voters were key to Barack Obama's two victories. He took 66 percent of voters aged 18-29 in 2008, and 60 percent of the cohort in 2012. In both elections, young voters made up almost 20 percent of the electorate. That means Clinton must ensure not only that millennials prefer her, but that they're enthusiastic and committed. She can't lose them to a GOP opponent but also can't let them revert to their pre-Obama election apathy.

Clinton is aware that she needs young voters and is making the effort to reach out. She launched her campaign through an online video, a medium more likely to reach a generation of cord-cutters. Then she hopped on the “Scooby van” -- a reference to the vehicle on the "Scooby-Doo" cartoon shows -- to start her campaign.

Republicans are trying to depict Clinton as the farthest thing from hip and connected to the youth. Rubio, in announcing his run, took a jab at Clinton, 67, as the candidate of “yesterday.” GOP strategist Karl Rove called her "something old and stale." Paul is selling fundraising stickers by arguing Clinton will “take us back to the past.”

Cruz, 44, used the Chipotle visit to take a swipe at Clinton. While speaking at an event in New Hampshire last weekend he suggested her drop-by was the extent of her outreach to young people. “You know, the Democratic version of this, I'm pretty sure, is Hillary Clinton having a conversation with a Chipotle clerk," Cruz said.

Narrow The Gap?

But Paul or Rubio might be just the candidate to narrow the age gap at the polls for the first time since 2000, when Republican George W. Bush won 46 percent of those age 18-29 -- only two points away from Democrat Al Gore’s 48 percent.

Paul is 52. He was the only 2016 candidate at the South by Southwest festival last month in Austin, Texas, a tech hub where he has centered his online operations. Paul's campaign is touting him as someone with "a conservative message that energizes young people." In the video that introduced him at his inaugural event in Louisville, Kentucky,  Yahoo reported, he aligned himself with “the Facebook generation" that doesn't support jailing kids for drug use, using tax dollars to bail out big banks, or letting the government peer into private records.

“Will you, America’s next generation of liberty lovers -- will you stand and be heard?” Paul asked the crowd.

Rubio, 43, is also framing the election as "a generational choice." Announcing his candidacy, he dismissed leaders who were "stuck in the 20th century" and said Clinton wanted "to take us back to yesterday."

“If their American dreams become impossible, we will have become just another country,” Rubio said. “But if they succeed, the 21st century will be another American century. This will be the message of my campaign and the purpose of my presidency.”