(CNN) As a presidential candidate, Donald Trump was emphatic that it is the government's responsibility to ensure that poor Americans can get the health care they need.

But in Trump's first days as president, it is becoming increasingly clear that he and his administration are open to making drastic changes to Medicaid -- a move that could make it difficult for Trump to fulfill his impassioned campaign promise to take care of the poor.

At a contentious Senate Finance Committee confirmation hearing on Tuesday, Rep. Tom Price, Trump's nominee to lead the Department of Health and Human Services, was pressed repeatedly by lawmakers to clarify his views on overhauling Obamacare -- a top priority for both the president and the GOP under the new administration.

In one particularly heated exchange with Democratic Sen. Bob Menendez, Price was asked whether turning Medicaid into a block grant program would mean fewer people would be eligible in the future. The decades-old entitlement program extends health coverage to low-income Americans, and Menendez noted that as an entitlement program, anyone who meets the criteria currently has the right to be covered.

"When you move to a block grant, do you still have the right?" Menendez asked.

"No, I think it would be determined by how that was set up," Price said.

Price's apparent acknowledgement that some low-income Americans may not be covered if Republicans move Medicaid over to a block grant system would mark a radical shift in the purpose that the program is supposed to serve.

During the campaign, Trump initially said he wouldn't cut Medicaid, but later expressed support for the block grant formula. But still, even as he publicly backed reforming the program, Trump has been adamant that the government's has a duty to help the poor.

"You cannot let people die on the street, OK?" Trump said at a CNN town hall last year. "The problem is that everybody thinks that you people, as Republicans, hate the concept of taking care of people that are really, really sick and are gonna die. We gotta take care of people that can't take care of themselves."

Tuesday, Price acknowledged Medicaid is vital but insisted it was troubled. The federal government should leave it to governors and state insurance commissioners to decide how best to cover their low-income residents, Price noted, and that he wants any Obamacare replacement bill to provide coverage options for every American.

Democrats expressed alarm, signaling that they would resist any fundamental changes to the decades-old federal program.

"I feel like the administration is creating a war on Medicaid," said Sen. Maria Cantwell, D-Washington.

'Did the President lie?'

The hearing also raised questions as to whether Price has ever discussed GOP plans to dismantle Obamacare with the new president.

In one particularly colorful exchange, Democratic Sen. Sherrod Brown, asked about an Obamacare replacement plan that Trump has been touting in public.

"President Trump said he's working with you on a replacement plan for the ACA which is nearly finished and will be revealed after your confirmation. Is that true?"

"It's true that he said that, yes," Price said, an awkward response that drew laughter from the hearing room.

"Not that he's every done this before but did the President lie? Did the President lie about this, that he's not working with you?" Brown tried. "Did he lie to the public about working with you?"

Price, again, would not say that he was working with Trump on an Obamacare alternative, saying instead: "I've had conversations with the President about health care, yes."

The nominee also struggled to satisfy Democrats when pressed an executive order that Trump's signed in his first day in office aimed at weakening Obamacare. Sen. Ron Wyden, the top Democrat on the panel, pressed the congressman to commit that "no one will be worse off" because of the executive order.

Price responded that he is committed to "working with you and every single member of Congress to make certain we have the highest quality of health care" and ensuring that "everyone has access to affordable coverage."

Wyden bristled, saying Price had "ducked the question."

Questions about his own health care plan

Price testified before the Senate Health Committee last week, but it is the Finance panel that will vote on advancing his nomination to the full Senate.

The timing of his confirmation is critical because Trump has said Republicans will release a plan to repeal and replace the Affordable Care Act as soon as Price is confirmed. GOP lawmakers have begun the legislative process to repeal large portions of Obamacare, but there is not yet clarity on crafting an alternative to the law.

Price, an ardent critic of Obamacare, has released a detailed proposal to overhaul the law. In last week's hearing, Price was pressed on multiple occasions to clarify Trump's -- as well as his own -- intentions on dismantling the health care law.

On Tuesday, Wyden blasted Price's past proposals, citing the congressman's budget and Obamacare repeal bills, which he said would hurt seniors by privatizing Medicare and gut Medicaid through block grants. And it would allow insurers to deny policies to sick Americans who didn't maintain continuous coverage.

"The Price plan takes America back to the dark days when health care worked only for the healthy and the wealthy," he said. "When I look at Congressman Price's proposals, I don't see the patient at the center of health care. I see money and special interests at the center of health care."

Several senators asked Price how he would carry out replacing Obamacare.

One of the top priorities, Price said, is to "lower the temperature" on the debate and let insurers know that "help is on the way." Concerns are mounting that insurers could be spooked by the divisions over repealing and replacing the health reform law and opt not to participate in the individual market in 2018, potentially leaving millions without coverage.

The nominee also reiterated that Obamacare has such high premiums and deductibles that people don't feel they have insurance. Coverage doesn't equal care in many cases, he noted.

"They've got the card but they don't have any care because they can't afford the deductible that allows them to get the care," he said.

On the popular Affordable Care Act provision that bans insurers from discriminating against those with pre-existing conditions, Price said: "Nobody, in a system that pays attention to patients, nobody ought to be priced out of the market for having a bad diagnosis. What we need is a system that recognizes that pre-existing conditions do indeed exist."

However, he did not go into detail on how he would protect these patients.

Ethics concerns

It wasn't just health care policy that had Price feeling the heat on Tuesday. The congressman again came under fire from Democrats for his financial investments, which have already raised a slew of ethics questions.

An orthopedic surgeon who has been a member of the House of Representatives for 12 years, Price has confronted accusations of investing in companies related to his legislative work in Congress -- and in some cases, repealing financial benefits from those investments.

Finance Committee staff Monday also released a bipartisan memo to lawmakers disclosing several red flags that were raised in the course of reviewing Price's tax returns and financial disclosure statements.

Pressed on these inconsistencies, Price reiterated: "Everything I did was ethical, above board legal and transparent," Price said. "There isn't anything that you have divulged here that hasn't been public knowledge."

On why he had underestimated the value of his stocks in an Australian pharmaceutical company, Price said he had misunderstood how to calculate their value.

"When asked about the value, I thought it meant the value at the time that I purchased the stock," Price said.

Sen. Orrin Hatch, the top Republican on the committee, kicked off the hearing by accusing his Democratic colleagues of holding up Trump's nominees.

Hatch said he had "never seen this level of partisan rancor when it comes to dealing with a president from an opposing party."