“I don’t think it’s fair to want to compare what we’re proposing today to what Obamacare might have been,” White House budget director Mick Mulvaney told NBC News Tuesday morning. “You have to compare it to what Obamacare is. And it’s a failure. By that comparison, this new program is going to be a tremendous success.”

Under Obamacare, the proportion of Americans without health insurance fell to a record low in 2015. Just 10.5 percent of Americans younger than 65 lacked coverage, down from 18.2 percent in 2010, before the law’s coverage expansions began.

Members of the House Freedom Caucus and Kentucky Senator Rand Paul quickly voiced their objections to the Republican replacement bill, dismissing it as “Obamacare Lite” and not the fuller overhaul of federal health care law they believe is needed.

“It won’t work. Premiums and prices will continue to spiral out of control,” Paul said Tuesday on Fox News, adding on Twitter that the “House leadership plan” won’t pass.

Paul said he was heartened by Trump’s tweet that the bill was just a starting point for negotiations. “I think he’s open-minded on this” and realizes “conservatives have a lot of objections” to the House GOP bill, he said on Fox.

A staff analysis prepared for the Republican Study Committee, an influential group of House conservatives, called the refundable tax credits “a Republican welfare entitlement.”

But the committee’s chairman, Representative Mark Walker of North Carolina, who had criticized earlier drafts of the bill, said the legislation had moved "in the right direction" and that his group’s steering committee will meet Tuesday evening to consider the changes.

“We are carefully reviewing this legislation looking in three main areas of shared conservative concern: protection of the unborn, elimination of Obamacare’s Medicaid expansion and ensuring the tax credits are fiscally responsible,” Walker said in a statement.

Republican Mark Meadows, also of North Carolina and chairman of the House Freedom Caucus said they too will meet Tuesday to discuss the legislation.

One senior Republican suggested that under his party’s bill, Americans would have to pay a larger share of their own health care costs.