The Democratic matchup between Tom Carper and Kerri Evelyn Harris pits one of Delaware's most successful centrists against a political newcomer being hailed as a harbinger of a coming blue wave itching to take on President Donald Trump.

It's a contest that many political watchers see as a bellwether for Delaware Democrats.

The state party, like much of Delaware's political establishment, is sticking with Carper, a former governor who has helped launch the careers of numerous Democrats and spent the last year positioning himself as a high-ranking backstop to Trump's conservative ideology.

Harris's embrace of Bernie Sanders-style policies is drawing support from a national network of progressives, along with a growing faction of largely young, energetic party activists in Delaware who believe they are the party's future.

Harris on Friday sought to drive home her place among the Democratic new wave by hosting a pair of rallies alongside Alexandria Ocasio-Cortez, an out-of-state congressional candidate who has become one of the more unlikely stars of this year's midterm election cycle.

Virtually unknown outside of New York City before this summer, the 28-year-old former bartender became a national icon of the insurgent progressive movement by winning a primary over U.S. Rep. Joe Crowley, a 10-term incumbent who chaired the House Democratic caucus.

"We can create an unstoppable force in our politics, and we can transform not just the Democratic Party but really the United States of America," Ocasio-Cortez told an audience of about 400 people at the University of Delaware's Trabant Center.

Harris is now hoping to repeat her success by besting Carper, who at 71 is both older than Crowley and has a longer tenure in Congress.

A 38-year-old community activist and U.S. Air Force veteran, Harris is only a few years removed from serving fried chicken at Royal Farms.

But she has gained ground by casting herself as the working-class antidote to a Democratic establishment she says has ignored average Americans in favor of corporate-friendly policies and Republican appeasement.

Her platform includes promises of a $15-an-hour federal minimum wage, Medicare for all, eliminating all student loan debt and abolishing the federal Immigration and Customs Enforcement agency – views some describe as extreme while others see as common sense.

"A lot of times, fear gets used to keep people from voting in their best interests," Harris said. "But there is nothing revolutionary about feeling that health care is a human right or believing that if you work hard, you deserve a livable wage."

Her campaign also is quick to point out the support Carper has received from corporate special interests and the voting record he has amassed during his three terms in the U.S. Senate and five in the U.S. House – a strategy designed to turn the experience that historically has been his greatest asset into a liability.

"He voted for the Keystone pipeline," Harris said during a debate sponsored by The News Journal. "He voted to confirm Rick Perry, who is bringing back coal plants that are polluting the air. He voted to allow Tyson chicken company to stop reporting their harmful emissions."

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Those messages have been amplified by groups outside of Delaware, including Ocasio-Cortez volunteers now working for the Harris campaign.

The partisan website The Intercept has written several pieces critical of Carper in recent weeks. The Working Families Party, a New York-based coalition of unions and activists, reportedly has spent close to $100,000 for a slew of online ads, mailers, door knockers and robo-texts on her behalf – almost as much as Harris has raised on her own. The Young Turks Network also has vowed to back her.

Carper is seeking to push past those groups by convincing primary voters in Delaware that his more-centrist brand of Democratic politics is still viable four decades after he was first elected to statewide office.

That bipartisan, middle-ground approach, he says, will be needed to secure passage of federal infrastructure funding and immigration reform while ensuring that special counsel Robert Mueller has the time and resources needed to complete his investigation of Trump.

"The thing I've heard the most from people in Delaware over the last several years is, 'Why can't you guys in Congress work together?'" Carper said. "Ted Kennedy once said he is willing to compromise on policy but not principle. I think that's good advice."

It's a style that has made Carper one of the most successful politicians in the state's history, with 12 victories in as many races over more than 40 years.

It's also an approach that might be in danger of becoming as outdated as both national parties seem to move further from the center with each election cycle.

"People are becoming more polarized and entrenched on both sides of the aisle as we see this natural slide away from this Third Way, Clinton-esque dogma," said state Rep. Sean Lynn, D-Dover, who endorsed Harris. "Kerri is not a radical swing, in my opinion, but she is a move slightly to the left of Sen. Carper."

Sensing that shift, Carper has stepped up his opposition to Trump, particularly over the last year. Perhaps most notably, he led the charge for former Environmental Protection Agency chief Scott Pruitt's resignation; called for enhanced vehicle emission limits; and vowed to oppose the nomination of Supreme Court nominee Brett Kavanaugh, a judge he previously helped confirm to the U.S. Court of Appeals.

He also recently came out in favor of a $15 minimum wage. Carper said he wants to tie the federal minimum wage to inflation, a measure he says already would have put the nation's base pay at $12, rather than the current level of $7.25.

To counter Harris's support from Ocasio-Cortez, Carper's campaign recently rolled out robo-calls and radio ads featuring former Vice President Joe Biden, along with testimonials from Wilmington Mayor Michael Purzycki and former Dover Air Force Base Col. Michael Grismer.

He also has collected endorsements from at least two groups with the power to move people to the polls: the Delaware AFL-CIO and the Delaware State Education Association, the largest union in the state.

"Tom Carper has devoted his entire adult life to that goal, and our state and country is better for it," said U.S. Sen. Chris Coons, D-Del. "I hear all the time from Democrats in Delaware who want their elected officials to oppose the President’s bad policies and harmful rhetoric, but they also want their elected officials to get things done and to be grounded in our state. That’s Tom Carper."

This could be Carper's last stand. When asked whether a fourth term in the U.S. Senate would be his last, he said he has not made up his mind but quoted a Rolling Stones hit from 1965, "This could be the last time ... I don't know."

Contact reporter Scott Goss at (302) 324-2281, sgoss@delawareonline.com or on Twitter @ScottGossDel.