When Trump was elected in November, Republican lawmakers enthusiastically joined his call to rewrite the tax code and dismantle Obamacare in the first 100 days of his presidency.
In early February, Trump promised a "phenomenal" tax plan by early March that never appeared. Mnuchin spoke on Feb. 23 of enacting tax reform by August. Spicer acknowledged this week that the timetable could be slipping.
Another senior White House official said the administration had assumed it would still be working on healthcare at this point, not tax reform yet. The official, not authorized to speak publicly, spoke to Reuters on condition of anonymity.
So far, Trump's tax campaign is a far cry from President Ronald Reagan's 1986 effort, in which Don Regan, as Treasury secretary and then White House chief of staff, spent many months developing legislation that won bipartisan support in Congress.
"The process under Reagan was much more developed, elaborate and long, and there was a strong bench of top-rate technicians putting things together," said Steven Rosenthal, senior fellow at the nonpartisan Tax Policy Center, a think tank.
Under Trump, he said, "None of that is happening."
'A Lot Simpler'
During the 2016 election campaign, Trump issued a tax plan that partly resembled one developed by House Speaker Paul Ryan, but Trump does not now appear wedded to either. It is a safe bet he will not lean heavily on the plan from Ryan, who drafted and championed the ill-fated plan to gut Obamacare.
"Trump now desperately needs a policy victory ... I would expect the president to play a much more activist role,” said Stephen Moore, a fellow at the Heritage Foundation, a think tank. Moore helped write the Trump campaign tax plan.
Mnuchin last week talked about a middle-class tax cut. He also said tax reform in many ways would be "a lot simpler" than healthcare, dismaying tax experts who said that is not so.