TV ads from the Business Roundtable are part of a multimillion-dollar effort by several groups to build early support for sweeping tax legislation. The messaging campaign pushes for tax cuts for working- and middle-class Americans. (Business Roundtable)

A coalition of some of the wealthiest forces in conservative politics is kicking off a major TV and ground campaign this month to drive momentum for a historic tax overhaul. The issue is now the GOP’s top legislative priority this fall, following the failure to enact an overhaul of the nation’s health-care laws.

The organizations behind the multimillion-dollar effort are hoping to avoid that fate by building early support for sweeping legislation, which they call “tax reform,” with a messaging campaign that promises to cut taxes for working- and middle-class Americans.

By another measure, however, these advocates may be repeating the mistake of health care, some GOP strategists say. Seven years ago, Republicans began rallying support — and winning elections — with a promise to “repeal and replace” the Affordable Care Act. But with no specific proposal to do so, they struggled this year to persuade Americans to support the effort.

Similarly, with retooling taxes, these interest groups are trying to sell “lower tax rates” to a wide swath of Americans without spelling out what taxes would be cut or for whom — and they are doing so long before Republicans are scheduled to begin forging a detailed proposal.

Already, some Republicans are weighing in with concerns about the approach.

(Business Roundtable)

“Public service announcements on behalf of a general idea are not politically effective,” said former House speaker Newt Gingrich, an adviser to President Trump. “People want to measure things by their own pocket. ‘What will my tax rate be?’ ‘Will my business have more money?’ ”

Gingrich is aligned with a group supporting tax cuts for the middle class and small businesses rather than more-sweeping changes — at least in the short term. “This is exactly what they did with health care, and it didn’t work,” he said. “People want to know how it’s going to work for them. With health care, they asked, ‘What about my mother’s preexisting condition?’ ”

Those behind the campaign say their goal is to build enough support among voters to pressure Congress to pass a tax-code overhaul by the end of the year — and give the president his first major legislative win.

“Right now, we’re in Step 1, which is working on the runway and building momentum for tax reform,” said Corry Bliss, executive director of the American Action Network, which spent $15 million on the health-care debate and now plans to plow up to $20 million more into pushing for the tax changes. “As we move forward, this will evolve into advocacy for specific aspects of tax reform.”

It is a timeline that top Republicans privately concede is optimistic, even though they and the administration have lent their blessing to the effort. After months of planning — including some contact with the White House — the deep-pocketed Koch network and wealthy donors who have poured millions into the American Action Network, which is allied with House Speaker Paul D. Ryan (R-Wis.), are driving the first serious flexing of financial muscle behind Trump’s agenda. The U.S. Chamber of Commerce is also poised to launch its own campaign.

In one TV ad financed by the Business Roundtable, a forklift operator drives across a factory floor as the words “lower tax rates” pop onto the screen. In an Americans for Prosperity video of a town-hall-style gathering, a crowd cheers as a congressman lauds a “grass roots” effort to cut taxes for “average Americans.” In an American Action Network radio spot, a man’s booming voice declares, “America’s tax code is sabotaging our economy.”

While the campaigns are emphasizing how average Americans would benefit from an overhaul of the federal tax code, the organizations behind them are also seeking a sharp reduction in the corporate tax rate, an idea that faces stiff opposition on the left. The backers include the kind of big-money and establishment players whose influence Trump decried during last year’s presidential campaign.

(American Action Network)

A coalition of liberal groups is ready to attack the Republican team effort in the coming weeks.

“We will be pulling back the curtain,” said Nicole Gill, executive director of the liberal group Tax March. “This is about giant tax cuts for the wealthy. The public will not stand for millionaires, billionaires and wealthy corporations getting more tax cuts — and that is what the Republican plan is all about.”

That’s one reason the conservative organizations and business groups are trying to lay the groundwork with a campaign that does not promote any specific changes to the law. While a wide range of groups across the right are united in a push to create a sense of urgency around a yet-to-be-written bill, they are already split over what it should say.

The groups behind the effort acknowledge the risk. They know they must convince middle-class Americans that this is their fight — and persuade them to inundate members of Congress over the next several weeks with demands for tax revisions at town-hall meetings and in letters to the editor, telephone calls, emails and tweets.

The hope is that the pressure will force members to start working on a tax bill in earnest when they return to Washington next month after the summer recess.

“We need to make sure that members of Congress know that average Americans are invested in tax reform, that they understand why it actually is important to them,” said Tim Phillips, president of Americans for Prosperity, a group financed by the billionaire industrialists Charles and David Koch and other wealthy conservatives. “If they think it’s just a group of wealthy corporations or powerful special interests battling it out to see who gets the best carve-outs, then this will fail.”

When Americans for Prosperity kicked off its tax campaign at the Newseum in Washington days ago, it ferried in dozens of supporters wearing blue jeans and T-shirts from small towns as far away as eastern Ohio.

During the roughly 40-minute event, speakers used the term “grass roots” more than a dozen times to characterize the campaign. And they touted nearly 60 events they will hold in communities across the nation over the next few weeks.

The Business Roundtable also announced it will spend millions of dollars this month on radio spots that will air on 250 local stations, as well as national cable television advertisements contending that “America has one of the highest tax rates in the world” and filled with images of factory workers in hard hats, couples fretting over stacks of bills, and struggling small-business owners.

The American Action Network has started airing radio advertisements that say “everyday working families are under attack.” Organizers are also working with local politicians and small-business owners to help them craft letters to news outlets. On Wednesday, the organization kicked off a $2.5 million television ad campaign featuring an unemployed metal worker.

“It’s a very compelling story,” Bliss said. “It’s about a laid-off worker whose job went to China. The middle-class tax cuts are about him and his family.”

Bliss said work on the campaigns began this summer and was coordinated through telephone calls and meetings with Republican leaders. Although it remains unclear how public a role the White House will play in the legislative effort, Trump has supported changes that would decrease corporate tax rates from 35 percent to 15 percent.

“We’ve been planning this launch for months,” Bliss said. “All the groups, both inside and outside [government], are meeting frequently, working together.”

Their opponents have been planning, too. The Not One Penny campaign — as in “not one penny” in tax cuts for the rich — includes a seven-figure ad buy in eight Republican-held congressional districts.

The ad will air later this month, Gill said, but most of the campaign’s efforts will come from volunteers who plan to confront lawmakers at town halls as others did when an attempt was underway to repeal the Affordable Care Act.

“We don’t have their money, but it’s hard to ignore your constituents when they are making practical, reasonable requests,” she said.

GOP strategists said their effort will succeed only if they take a lesson from the health-care debacle and go on the offensive early, rolling out a compelling message that persuades voters that upending tax rules will benefit average Americans.

“One of the main reasons for the failure of Obamacare repeal was the lack of any coherent message strategically to explain why Republicans were doing what they were doing, other than it was a campaign promise,” said Steven Law, a former chief of staff to Senate Majority Leader Mitch McConnell (R-Ky.) who now runs a collection of GOP-allied groups.

“We’re concerned already that Republicans are falling into the same trap again, arguing that one of the main reasons to do tax reforms is we haven’t done it in 31 years,” Law added. “That’s not going to cut it. We think the argument needs to be presented in terms that regular people can relate to.”

One of Law’s organizations, One Nation, is launching polls, focus groups and message-testing to determine the most effective way to sell the tax overhaul. Law said it then plans to share its research with other organizations.

The role of the Koch network in the campaign illustrates how the administration has the backing of new allies in this fight. Last year, relations between the Trump campaign and the Kochs were frosty; the well-funded conservative operation pointedly stayed out of the 2016 campaign, and Trump mocked the Koch brothers as puppeteers who control politicians. After he took office, network officials spoke out against an early version of the administration’s travel ban and opposed a possible border tax on imports.

But the possibility of enacting a substantial tax overhaul has brought the network and Trump in alignment. Koch officials are working closely on the effort with Marc Short, a former top network official who serves as the White House legislative liaison, and Vice President Pence is scheduled to deliver the keynote speech at Americans for Prosperity’s annual summit in Richmond later this month.

“To have the House and Senate leadership and the president have a set of principles they have agreed to — that’s significant,” said AFP’s Phillips. “It doesn’t assure anything, but it is a dramatic difference from the health-care effort. And failing on health care certainly has raised the stakes on tax reform for Republicans.”

Damian Paletta contributed to this report.