Mnuchin’s money shot underscored the awkwardness for the White House of selecting multimillionaires as the principal salesmen for a tax bill it claims will boost workers’ wages and cut taxes for the average middle-class family. Mnuchin and fellow Goldman Sachs alum Gary Cohn have consistently fumbled that pitch, in part due to their own backgrounds, said Democrats and Republicans watching the effort.

While the House passed its version of the bill earlier this month, Republicans who see final passage as a make-or-break moment for the party are worried about potential turbulence in the Senate, which is expected to vote on its version this week.

Six Senate Republicans are still withholding their support for the tax cut package — enough to tank it — and others in the party said they don’t want the difference-maker to be a lack of good messengers from the White House. And so far, the pitches don’t appear to be helping. A recent Quinnipiac University poll found that 52 percent of voters oppose the GOP tax plans, and only 25 percent support them.

“If this thing does fall all apart on the shoals,” said one former top Hill aide, “maybe the difference is the lack of good messengers. On a nail-biter, you don’t want any margin of error.”

And critics in both parties said Mnuchin and Cohn may have helped create one.

In September, Cohn told reporters that with the $1,000 that he said the average American family is likely to save from the proposed tax plan, they “can renovate their kitchen, they can buy a new car.” The offhand comment delivered to reporters in the White House briefing room seemed to underscore how out of touch the Hamptons-summering millionaire was with the expenses facing everyday Americans.

“The most excited group out there are big CEOs, about our tax plan,” Cohn, the former president of Goldman Sachs, said in an interview with CNBC earlier this month. The Senate version of the tax bill would reduce the corporate tax rate to 20 percent from 35 percent starting in 2019.

A few weeks later, speaking in front of an audience of chief executives gathered in Washington, Cohn expressed shock that their hands stayed in their laps when they were asked whether they planned to increase investment under the new tax plan. “Why aren’t the other hands up?” Cohn wondered out loud.

The bumbled pitches for a must-win bill have left Republicans exasperated at a time when the global and domestic economies are rallying — and Republican lawmakers are eager to have a legislative accomplishment to point to on the campaign trail during next year’s midterm elections. “All kinds of stuff is breaking their way, and they can’t get out of their own way,” said one prominent Republican close to the Trump administration.

Some Republicans on Capitol Hill have started to distance themselves. House Speaker Paul Ryan earlier this month asked the White House not to send Mnuchin to the Hill to talk with Republican lawmakers about the bill, according to two people familiar with the discussions — though Ryan has praised the Treasury secretary’s ability to improve the legislation itself.

“There were some testy conversations” between Ryan and Mnuchin, according to a White House official — in particular, over Mnuchin’s attempts at bringing lawmakers on board. He approaches them, the official said, “with a certain arrogance.”

Ryan’s spokesman Doug Andres denied that the speaker’s office made that request. “That is definitely not anything the speaker or our office has ever said,” Andres said. But the general view of Mnuchin from the Hill, according to another former top operative on the Senate side, is that Mnuchin “doesn’t have a deft touch on the working-man arguments.”

Several Republicans say the political pressure for congressional Republicans to pass a bill is so great that any self-inflicted wounds from the Goldman duo are unlikely to matter much.

“The strongest force behind this bill, the one that will make the biggest difference in the end, is the political imperative for Republicans to pass it,” said Brian McGuire, a former chief of staff to Sen. Mitch McConnell.

The White House said its sales pitch doesn’t depend solely on Mnuchin and Cohn — and that the lead cheerleader for the bill is the president himself.

“The president’s entire team, led by Secretary Mnuchin and Gary Cohn, have been sweeping the country talking to Americans about how tax reform will give them a pay raise and make our economy great again,” said deputy press secretary Lindsay Walters.

Despite his 12-day trip to Asia during a main negotiating phase of the bill, President Donald Trump has delivered at least eight tax reform-related speeches across the country, including his event in Harrisburg, Pennsylvania, with truckers in October, a second White House official said.

There, Trump promised that the average American household would see its wages rise by $4,000 under the tax plan, because of a provision encouraging American companies to bring home profits from overseas. But he provided no evidence to back up the claim. That didn’t matter from a sales perspective.

“‘Saturday Night Live’ opened that weekend with our truckers event,” the second White House official said. “That’s a win. Mnuchin and Cohn do not drive a news cycle like a presidential event.” In the “SNL” skit, however, Alec Baldwin, as Trump, engaged in an extended riff about how the president couldn’t steer away from provocative social issues and jokes about retiring Tennessee Republican Sen. Bob Corker long enough to actually pitch the tax bill.

The official also said that the administration’s internal polls show that the president’s message has been effective. “We took nuggets of the things the president was saying [about tax reform] and polled it, asking, do you agree with this statement,” the official said. “I think nine of those nuggets polled at 80 percent or higher among likely voters. We’re very confident of the message we’ve been selling.”

The White House also highlighted other surrogates outside the Goldman class, including budget director Mick Mulvaney, a Southerner with a middle-class, entrepreneurial background who has been making the media rounds.

And the president’s daughter Ivanka Trump has been pairing local events across the country with interviews on friendly Fox News programs like “Hannity,” “Fox & Friends” and “Tucker Carlson Tonight,” where she has been given a platform to talk specifically about the child tax credit, long her pet issue.

Veterans Affairs Secretary David Shulkin, counselor Kellyanne Conway, Small Business Administrator Linda McMahon, Agriculture Secretary Sonny Perdue and Labor Secretary Alexander Acosta have also been participating in local events to pitch tax reform.

But it’s Cohn and Mnuchin who have emerged as the dominant faces of the White House sales pitch — and who have Democrats disbelieving their good fortune that the Wall Streeters are allowed to continue to be out front, selling the bill.

“These guys are the ultimate Wall Street insiders,” said Brian Fallon, who served as press secretary for Hillary Clinton’s 2016 campaign. “Any savvy public relations person would say that they should be a mile away from the salesmanship for the bill. But they’re out front. It’s just a clue that there is no one senior in the White House to say to them, you’re benched.”