WASHINGTON — When it comes to Washington’s endless tax debates, Erin Calvo-Bacci — a small-time chocolate maker from Swampscott — spells out her frustration in bitter terms.

“I’ve built something and we’re surviving,’’ Calvo-Bacci says in a national cable TV advertisement, eyes wet and voice cracking, after displaying her signature confection. But if some Republicans succeed with their latest initiative, she says, it “is going to kill us.’’

She is talking about the so-called “border adjustment tax’’ that House Speaker Paul Ryan champions as one radical part of his proposed overhaul of America’s byzantine corporate tax code.

This provision has triggered a storm of debate that, in its roughest outlines, pits the nation’s importers and retailers against its exporters and multinational companies.

The simple, emotional appeal of retailers such as Calvo-Bacci, the owner of CB Stuffer in Swampscott, shows why pro-Ryan forces are facing stiff headwinds on Capitol Hill. The National Retail Federation is putting Calvo-Bacci’s face on the airwaves in California, Texas, and Kentucky in a bid to influence key members of Congress to vote against Ryan’s plan.

The proposal, Calvo-Bacci says, would jack up prices on the imported sugar and chocolate she buys to make her goods, including her showcase item, jumbo peanut butter cups — “5.4 ounces,’’ says her website, “of chocolate and peanut butter heaven.’’

“You can’t grow chocolate here. So we have to import these items,’’ she says in the video. “It’s going to put businesses like mine out.’’

Calvo-Bacci is a relatable foot soldier in a lobbying brawl that pits many national retail chains against an array of corporate titans, including General Electric, which recently relocated its headquarters to Boston, and Waltham-based Raytheon Co.

Making Washington’s tax debate understandable could be key to the outcome. Importers say that adding a new levy on imported goods would force consumers to pay higher prices. Domestic manufacturers, multinational companies, and exporters say it would level the global playing field and pave the way for eliminating the current loophole-ridden corporate tax system.

President Trump, who made overhauling the tax code a top campaign promise, continues to talk big on tax reform. On Friday, he announced plans to unveil his plan this week, promising that it would include steep cuts for businesses and individuals — “bigger, I believe, than any tax cut ever.’’ He provided no details.

The tax-overhaul effort has to date been bogged down by a lack of clear direction from the White House and intraparty GOP unrest. Democrats, meanwhile, are increasingly demanding to see Trump’s tax returns before considering any legislative proposals.

Treasury Secretary Steve Mnuchin acknowledged in aninterview with the Financial Times last week, the day before Trump’s vow for fast action on taxes, that completing tax legislation would be delayed until the fall, at the earliest. A previous August deadline, after the health care debacle, was “not realistic at this point,’’ he said.

Ryan’s overall proposal would be a game-changer in the tax world. But it animates wonks and corporate chieftains more than anyone, and is difficult for average voters to comprehend.

It would eliminate the 35 percent corporate tax on income and replace it with a 20 percent tax on the profits a company makes from selling goods in the United States – whether those goods are imported or produced domestically — as well as services consumed here.

Profits generated from exports would be exempted.

The fierce opposition mounted to Ryan’s bid for a border adjustment tax as part of that overhaul has taken its toll, too. Numerous GOP senators have expressed serious reservations about the idea, even outright opposition, imperiling its fate in that chamber.

The White House has sent conflicting signals about its support for Ryan’s blueprint.

On the other hand, no one else has come up with a viable way to fund big corporate tax cuts. “In the absence of an alternative, a plan often becomes the plan,’’ said Michael Steel, a veteran of former GOP House Speaker John Boehner’s office and a managing director at the public affairs consulting firm Hamilton Place Strategies.

No one in Massachusetts’ all-blue delegation has embraced Ryan’s plan, nor have Democrats broadly.

“I don’t see the border adjustment tax making much headway,’’ Representative Richard Neal, the top Democrat on the tax-writing Ways and Means Committee, said in an interview on Friday, noting the trouble that Ryan is having winning over members of his own party.

Proponents, including a business group called the American Made Coalition, argue­ that this shift would bring the United States in line with the way the rest of the world taxes corporations. They say it would end a competitive disadvantage that big US-based multinationals face because their profits are effectively taxed twice — once in the country they sell their goods in, and again if they bring those profits home.

Ryan’s plan would induce companies to invest profits in US factories and jobs, its supporters say. It also would make good on Trump’s campaign promises to encourage manufacturers to return to the United States, they argue.

What’s more: The change would generate up to $1 trillion over 10 years in new revenue needed to replace the old corporate tax system.

“Over the past generation, the US has done very little to help our manufacturers or workers. Our tax policy favors imports, not exports,’’ GE chief executive Jeff Immelt wrote in his annual letter to shareholders. “We are hopeful that the new administration will ‘level the playing field’ for US companies.’’

American Made members say it’s misleading for their opponents to focus on just the border adjustment tax, and not on all of the tax reform elements Ryan is pursuing.

“The House tax reform blueprint would create 1.7 million new jobs [and] increase wages nearly eight percent,’’ said John Gentzel, spokesman for the American Made Coalition. Opponents “are doing everything to try and stop tax reform, even continuing to use misleading facts and figures to keep the current broken tax system.’’

But retailers big and small say the tax change would force them to increase the prices they charge customers, cut jobs, and in the case of tight-margin operations like Calvo-Bacci’s chocolate business, maybe even shut down.

“Larger companies may be able to absorb this’’ or pass on the cost increases to their customers, Calvo-Bacci said in an interview with the Globe. “For me, it’s about if you don’t fight, no one is going to be around to fight for you.’’

A coalition of retailers that includes Walmart, Target, and Costco Wholesale estimates that higher prices at the store and pump would cost American families $1 trillion over 10 years. The billionaire Koch brothers also are opposing it.

“I don’t care if you’re a competitor, everybody is united in this,’’ said Dave Ratner, owner of Dave’s Soda & Pet City in Agawam, Mass., who is the subject of a National Retail Federation video online. There’s not a dog crate, collar, or toy in his store that’s not imported, said Ratner.

“It literally affects every single thing that’s in our stores,’’ Ratner said in an interview. “I do feel in the bottom of my heart that it’s a job-killer.’’

Victoria McGrane can be reached at victoria.mcgrane@globe.com.