Fresh off his high from watching the House pass Obamacare replacement legislation in May, President Trump invited all 248 Republicans in the lower chamber over to the White House for an impromptu Rose Garden celebration. “Premiums will be coming down. Deductibles will be coming down. But very importantly: It’s a great plan,” the president, surrounded by rank-and-file members, boomed from the podium.

Two months later, Trump told a roomful of GOP senators the House-passed bill was “mean.” It was a stunning reversal from what he had told Americans on that sunny afternoon in the Rose Garden, and the first of several missteps that many claim contributed to Republican’s ultimate failure on healthcare — and worry about a repeat on tax reform.

“He proved last time to be an enormous liability,” veteran GOP consultant Rick Tyler told the Washington Examiner hours before House Republicans were originally scheduled to unveil their tax reform plans (this has since been delayed until Thursday). “No one was talking about the benefits of what it was they were trying to get done. They were talking about Donald Trump not understanding something or Donald Trump attacking so and so, or ‘Donald Trump said this.’”

As the White House begins plotting an expensive campaign to sell tax reform to the public, some worry there’s only a “50-50 chance” Trump will triumph in his message discipline.

A Republican strategist close to the White House said Trump has shown signs of improvement, citing a series of recent speeches the president has delivered on tax policy in which he put pressure on vulnerable Democrats and spoke only the words on his teleprompter.

But “you never know how he’s going to react if, say, [Republicans] can’t agree on a corporate rate of 20 percent or there are multiple defections,” the strategist said.

Over the course of six months — from the time the House passed its Obamacare repeal bill to the September failure of Graham-Cassidy, a last-ditch plan to redirect federal healthcare funding to the states — Trump targeted a slew of GOP lawmakers on Twitter in bitter tweets about their positions on healthcare, vacillated between wanting to kill the 2010 law legislatively or let it collapse on its own, and abandoned his key campaign promise to oppose Medicaid cuts.

In one instance, the president urged Republicans to immediately repeal Obamacare and then work to devise a bipartisan replacement bill, before suggesting less than 12 hours later that they should let the law implode on its own.

Minus the contradictory follow-up tweet, Trump used social media in a similar fashion last week to promise that Republicans will not make adjustments to 401(k) retirement savings plans.

“There will be NO change to your 401(k),” he tweeted, flexing his muscle over the congressional tax-writing committee. “This has always been a great and popular middle class tax break that works, and it stays!”

“I thought that was the most interesting thing he did and the lesson he should have learned most,” Tyler said. “When [Trump] said we’re not going to touch 401(k)s, I’m sure a lot of people were relieved, and he thought he was being the champion of them.”

“But what he really did is say, ‘The Republicans will be producing a terrible tax plan if they do include changes to 401(k)s, and you shouldn't support it,” he continued, pausing to ask “How does that help him?”

Some Trump allies praised the tweet, however, claiming it showed Trump possesses an acute understanding of how tax reform should be pitched to the public.

“What he is trying to do is sell it to the broadest group possible,” GOP strategist Ford O’Connell told the Washington Examiner. “What Republicans are going to have to do with tax reform is quash anybody who wants to spoil it. So, imagine if someone doesn’t know about 401(k) stuff, and they’re told, ‘Hey, Republicans are going to destroy your 401(k).’ That’s why he said that.”

Trump and House Speaker Paul Ryan huddled Tuesday to discuss the timeline for tax reform, something the White House and congressional Republicans are hoping to accomplish before Washington empties out for Thanksgiving. An aide to Ryan, R-Wis., said the unveiling of the tax bill Wednesday would be followed by swift “committee and floor action in the coming weeks.”

The meeting followed a roundtable where Trump asked business and various industry leaders to “redouble” their efforts to promote tax reform over the coming weeks, a push that will supplement a multi-million dollar ad campaign by America First Action, an outside group aligned with the White House.

The West Wing has also beefed up its communications team with temporary staffers who have been tasked with crafting talking points and highlighting positive developments related to tax reform, according to a source familiar with the hires.

For those new hires, and for the president himself, O’Connell had one messaging tip to offer based on past mistakes:

“The White House cleared a major hurdle when Congress passed the budget, but now they need to focus on building even more momentum. And they should be cautious about doing the old Irish jig on the White House lawn.”