Conservatives in the House and Senate haven't given up hope that they can reshape Republican Obamacare replacement legislation to be more to their liking, despite mixed signals from the White House and congressional leadership.

"What we have now is an opening bid," Rep. Mark Sanford, R-S.C., said during a Tuesday press conference in reference to the American Health Care Act unveiled by top Republicans. Sanford appealed to the president's reputation as a tough negotiator.

"Inasmuch as President Trump views many things as a negotiation, I'm quite sure he would rarely take any party's opening bid," he added. "The debate that is forming will allow conservatives to enhance and improve what has been proposed, and I think this could represent a win for patients, healthcare providers, and the taxpayer alike."

Right now, the most conservative members of Congress appear to be on a collision course with the rest of their party. Conservatives would like the clean Obamacare repeal language of 2015 to be the starting point, not the bill introduced Monday that some called "Obamacare Lite."

The Trump administration seemed open to talking it over. Health and Human Services Secretary Tom Price repeatedly called the bill a "work in progress" from the White House on Tuesday.

But President Trump made a point of endorsing the main Republican plan, while Vice President Pence argued any "no" votes from the right were effectively votes to keep Obamacare in place. House Speaker Paul Ryan, R-Wis., guaranteed the bill would pass his chamber.

Those signals didn't stop conservatives from introducing their own rival legislation. Important outside conservative groups have denounced the main Republican replacement plan as "Ryancare." Those opponents include Heritage Action, Club for Growth, FreedomWorks and the Foundation for Government Accountability.

For conservatives, the key is whether Ryan can actually get 218 votes in the House for the American Health Care Act in its current form.

"If they don't have 218 votes there will be a negotiation and conservatives will have a seat at the table," said Sen. Rand Paul, R-Ky., at the press conference with House Freedom Caucus members and Sen. Mike Lee, R-Utah.

Paul said regardless of the public positions taken by the White House and congressional leadership, the Trump administration wouldn't be reaching out to skeptical conservatives if it wasn't open to a negotiation.

The president himself later tweeted that he hoped his "friend" Paul would come around to support "the new and great health care program" because of their shared knowledge that Obamacare is a "disaster." By contrast, Paul urged conservatives to withhold their support, at least for now, until they can extract changes and get a better bill.

Rep. Mark Meadows, R-N.C., said Pence's message to his Freedom Caucus was that the final legislation was "still up for negotiation."

"I think [what] the president and vice president [are] saying is that the foundation is a good foundation," he said. "We might disagree with that." But Meadows signaled a willingness to improve the legislation.

Rep. Jim Jordan, R-Ohio, said conservatives were the only ones offering what Republicans promised voters on healthcare reform: "repeal Obamacare and replace it with a market-centered, doctor-centered plan that actually brings down the cost of insurance, brings down the cost of healthcare and provides affordable insurance opportunities for all Americans."

Jordan called the leadership-backed plan "Obamacare by another form" rather than a fulfilment of what the GOP promised.

Lee described the bill as a "blown opportunity" and "step in the wrong direction."

Conservatives hope to see repealing and replacing Obamacare play out according to a process similar to its initial passage. Back then, the Democratic majority negotiated with itself to produce a bill that could pass and reach the president's desk.

During these 2009-10 negotiations, some of the most liberal elements of the Democratic healthcare program were struck from the bill, including the government-run public option. At one point, a small group of anti-abortion Democrats in the House appeared to hold the decisive votes in passing Obamacare, causing then House Speaker Nancy Pelosi, D-Calif., to temporarily agree to tough restrictions on abortion funding.

In that sense, the Affordable Care Act was more a product of Congress than President Obama, and the same will be true of any replacement under Trump.

Here's one thing conservatives don't want to repeat, however: Democrats mostly negotiated with their party's moderates in writing Obamacare. Republicans have a smaller number of moderates to contend with, but they also have smaller majorities.

Democrats could afford to lose a number of votes from both the left and the center because they had nearly three-fifths majorities in both houses of Congress. Republicans can only spare two votes in the Senate even when pushing healthcare reform through via reconciliation.

If the key defectors are conservatives like Paul, Lee and Sen. Ted Cruz, R-Texas, they could pull the final product to the right. If the defectors are moderates like Sens. Susan Collins, R-Maine, and Lisa Murkowski, R-Alaska, the bill will be unchanged or pulled to the left.

Four to five GOP senators appear to oppose repealing the Medicaid expansion, for example.

The narrowness of the GOP's congressional majorities and the need to win votes from across the party's ideological spectrum are factors in why the replacement is a disappointment to conservatives in the first place. Moderates might be more willing to live with Obamacare staying fully on the books than conservatives.

"We have to admit we are divided on replacement," Paul said.

The question is whether conservatives can turn that admission into an Obamacare replacement they like better.