Vice President Pence and Speaker of the House Paul Ryan applaud as President Donald J. Trump delivers his first address to a joint session of Congress from the floor of the House on Feb. 28 2017. (Jim Lo Scalzo / Pool/EPA)

President Trump ascended the bulliest of pulpits Tuesday to address a joint session of Congress. It turns out it was his fellow Republicans who needed some bullying — specifically, on their plans to repeal and replace the Affordable Care Act.

The leader of the Republican Party took some tentative steps in his address to the joint congressional session toward a position in the Obamacare fight looming over Capitol Hill. But the president’s words sparked as much debate as they quashed.

The federal government, Trump said, “should help Americans purchase their own coverage, through the use of tax credits and expanded health savings accounts.”

By specifically mentioning “tax credits,” Trump appeared to side with House Speaker Paul D. Ryan (R-Wis.) in a key intraparty debate over what the ACA’s replacement ought to look like. Influential conservatives in the House and Senate have balked at offering refundable tax credits to help Americans buy insurance, advocating instead for a less expensive tax deduction.

Ryan’s staff and House GOP leaders immediately claimed Tuesday that Trump had moved to settle the dispute.

(Zoeann Murphy/The Washington Post)

“This was a clear sign that President Trump is working in sync with us in the House and Senate and wants to make sure we get this done quickly,” said Rep. Steve Scalise (R-La.), the House majority whip. “We’ve laid out a lot of specifics, and I think you saw the president embrace and endorse a lot of those key components tonight.”

But on Wednesday, as key House committee chairmen briefed Republican senators on their health-care plans, there was still significant unrest.

Rep. Mark Meadows (R-N.C.), chairman of the House Freedom Caucus and an outspoken critic of refundable tax credits, said Trump’s remarks did not constitute an endorsement of the Ryan plan.

“I didn’t interpret it to mean that it was advanced or refundable,” he said, referring to the nature of the tax credits.

Rep. Raúl R. Labrador (R-Idaho), another conservative hard-liner, made a similar point: “He was making sure that he wasn’t taking a position on something that he knows we’re disagreeing about.”

The tax-credit issue has become a flash point between GOP leaders and their conservative flank, rooted in the amount of government spending it would take to achieve adequate health coverage in the ACA’s absence.

The Ryan-backed plan would offer a refundable tax credit that would provide the same sum to taxpayers of all income levels, even those who pay little income tax because of their low incomes. It would also be “advanceable” — that is, distributed throughout the year — to spare insurance buyers from having to pay their premiums in full before seeking reimbursement on the following year’s tax return.

Conservatives such as Meadows have argued that refundable tax credits are too expensive and constitute a new federal entitlement, while advanceable credits, they say, are too prone to fraud and abuse. But both have been a part of past GOP plans — including Ryan’s “Better Way” blueprint and an ACA replacement plan advanced by new Health and Human Services Secretary Tom Price when he was a House member, one that many conservatives, including Meadows, co-sponsored.

[Medicaid exposes rifts within the GOP over the program’s future after ACA ]

Rep. Kevin Brady (R-Tex.), chairman of the House Ways and Means Committee, and Rep. Greg Walden (R-Ore.), chairman of the House Energy and Commerce Committee, briefed GOP senators Wednesday afternoon in a bid to build bicameral consensus on the developing House framework.

Ryan and Price spent Wednesday morning talking directly with skeptics of the House approach. Several members said they met directly with Price to discuss the administration’s position on key elements like the refundable tax credits and the fate of the ACA’s Medicaid expansion.

The takeaway: Tax credits aren’t up for debate.

“The president is carrying about 88, 90 percent of the Republican base,” Rep. Mark Walker (R-N.C.), chairman of the Republican Study Committee, said Wednesday, two days after issuing a statement opposing refundable tax credits. “Our voters said, ‘Let’s go and move,’ and that’s a factor.”

Another fault line is what to do with Medicaid, the government’s health program for low-income Americans that was expanded to 11 million people as part of Obamacare.

Other key conservatives kept their powder dry Wednesday. Sen. Ted Cruz (R-Tex.) declined to say whether he would support or oppose a GOP health-care bill that included tax credits.

“I understand that our good friends in the media want to focus on areas of division,” Cruz said. “The president laid out general principles of reform, and right now both houses of Congress are debating the specifics of those reforms.”

Senate Republicans cannot afford widespread internal dissent. GOP leaders are hoping to use special budget rules to pass repeal by a simple majority vote, and even so, they can lose no more than two of 52 Republican senators.

One Republican, Sen. Rand Paul of Kentucky, has put forth a tax-deduction-based plan that has been embraced by hard-line House conservatives. Leaving Wednesday’s briefing, Paul said he would not support refundable tax credits: “I’m not in favor of keeping parts of Obamacare.”

GOP lawmakers of all ideological stripes said that Trump needs to take a more aggressive role in refereeing the intraparty disputes.

“The president is key to getting anything we do in health care across the finish line, and I look at last night as the beginning of that,” said Rep. Patrick J. Tiberi (R-Ohio), chairman of the Ways and Means subcommittee on health.

Rep. Mark Sanford (R-S.C.), who has put forward a tax-deduction-based bill endorsed by the Freedom Caucus, acknowledged that it will be challenging if Trump supports tax credits.

“It becomes very difficult for Republicans to go a different course, although I would hope that we would,” Sanford said Tuesday before Trump spoke. On Wednesday, he, like other conservatives, split hairs: “He didn’t say ‘refundable’; he said ‘tax credits.’ ”

Trump has shown a willingness to prod and cajole congressional leaders into action, and Tiberi said the White House would only get more willing over the coming weeks to intervene in intraparty squabbles.

Rep. Chris Collins (R-N.Y.), an outspoken Trump ally, said fellow GOP lawmakers will ultimately need to support a consensus plan.

“We as a Republican Party have to get this passed, otherwise next term’s midterm elections would not be a pretty sight,” he said. “When a good bill finally hits the floor would they really vote against it?”

Ed O’Keefe, Sean Sullivan and Dave Weigel contributed to this report.