Washington (CNN) Senate Republicans unveiled their newest health care bill Thursday as they continue to search for the majority needed to repeal and replace Obamacare.

Now, it's up to senators to decide if they like it.

The new bill includes major changes to the original. One of the most significant was the inclusion of an amendment by Texas Sen. Ted Cruz, which would allow insurers offering Obamacare plans to also offer cheaper, bare-bones policies. The amendment was included in an effort to earn more conservative support, but could also drive away some moderates who fear the amendment could drive up premiums for those with pre-existing conditions.

It also contains significant new funding for opioid treatment and money for states meant to lower premiums for high-cost enrollees. But it would keep two Obamacare-era taxes on the wealthy and maintains significant cuts to Medicaid, meaning 15 million fewer people could insured by the program by 2026.

Majority Leader Mitch McConnell is still in search of the 50 votes he needs to pass the bill -- he can only afford to lose two senators -- but the hope for leadership is that a few changes may be able to finally get Republicans on a path to repeal and replace Obamacare after seven years of campaign promises.

Already on Thursday Sen. Rand Paul of Kentucky said he wouldn't even support the motion to debate the bill on the floor.

Sen. Susan Collins, a Republican from Maine, also told reporters that she would not vote for the motion to proceed unless she saw significant signs from the nonpartisan scoring agency -- the Congressional Budget Office -- that the cuts to Medicaid would be less severe than she anticipated.

"The only thing that can change that is if the CBO announcement, which come out on Monday, indicates that there would be far fewer in Medicaid than I believe there are now," Collins said.

Emerging from a meeting with fellow senators Thursday, Republicans were cautiously optimistic with many saying they needed to sit down to read the bill before they made any final decisions.

Sen. Jeff Flake, an Arizona Republican, said he was "still thinking" as reporters swarmed him.

Sen. Bill Cassidy of Louisiana said "I always want to say I criticized Nancy Pelosi for saying 'we got to pass the bill to know what's in it.' I want to know what's in it before I say I'm gonna pass the bill."

Moderates from Medicaid expansion states continued to voice their concerns about the new bill. West Virginia Republican Sen. Shelley Moore Capito said she was "very much undecided" and would meet once again with McConnell this afternoon.

"I still think there's a lot of unanswered questions particularly coming from a state that has a high percent of people with pre-exiting conditions," she said.

Alaska Sen. Lisa Murkowski, one of the GOP holdouts, was unhappy that reporters had seen a summary distributed to lobbyists before she had seen the bill.

Asked if she was upset by how the process unfolded, she said "yes."

"I think that as a courtesy to those of us who are actually making the decisions that we would actually have an opportunity to see it first," Murkowski added.

A major question remains whether President Donald Trump can use his bully pulpit to actually move senators.

Trump has lobbied for Republicans to move quickly. The President said Wednesday he would be "very angry" if Republicans can't pass the bill.

"I don't even want to talk about it because I think it would be very bad," Trump said in an interview with the Christian Broadcasting Network. "I will be very angry about it and a lot of people will be very upset."

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What's new?

The revised legislation has $45 billion in opioid treatment funding -- a top request from senators like Rob Portman of Ohio and Shelley Moore Capito of West Virginia -- as well as in state stabilization money aimed at lowering premiums for high-cost enrollees.

But another concern for moderate senators -- that the Senate bill makes steep cuts to Medicaid funding -- was not addressed in the new version. The original bill calls for slashing $772 billion from Medicaid by 2026, compared to current law, leaving 15 million fewer people insured by the program.

In a retreat from a key GOP promise, the bill would also keep two Obamacare-era taxes on the wealthy. That came as members said they worried about the optics of cutting taxes for the rich while also slashing funding for subsidies that go to help low-income people to buy insurance. Retaining the taxes, which saves the federal government $230 billion over 10 years, provides McConnell money to help boost the stabilization fund, sources said. But it is also likely to infuriate conservative lawmakers and lobbying groups.

The legislation would allow consumers to use their health savings accounts to pay their premiums for the first time, which Cruz called "very significant."

Graham plan

Also Thursday, GOP Sens. Cassidy and Lindsey Graham of South Carolina proposed an alternative approach to replacing Obamacare that would keep much of the federal taxes in place and sending that money to the states to control.

They say that one of the primary reasons Republicans are having such a hard time agreeing is because they are working from the Obamacare template -- particularly federal control of health insurance.

Cruz amendment

Cruz's so-called Consumer Freedom amendment is considered contentious among Republican senators with some moderates having raised concerns that it could hurt those with pre-existing conditions. The amendment would allow insurers that offer Obamacare plans on the exchanges to also sell policies that are exempt from certain of the law's mandates. That could allow carriers to provide less comprehensive plans with lower premiums, which would likely attract younger and healthier Americans.

But that would leave the sicker, more expensive consumers in the Obamacare plans, causing their premiums to spike.

Offering Obamacare plans will also make insurers eligible for new federal funding aimed at helping insurers pay for high-cost enrollees.

Sen. Mike Lee -- a Utah Republican and close Cruz ally -- tweeted Thursday morning to say that he has not seen the newest version of the Cruz amendment included in leadership's health care bill and was unsure if he could support it.

There's also no guarantee the Cruz amendment -- in whatever form -- will even get a Senate vote. It could be stripped from bill at any time as GOP leaders negotiate and work their way through Senate rules.

Insurers, who have largely stayed on the sideline in the health care debate, voiced strong opposition to the amendment, saying it would destabilize the individual market. Two major lobbying groups said this week that it would create two sets of rules and make coverage unaffordable to those who are sick.

"I'm writing to make clear my view on how the 'Consumer Freedom Option' is unworkable as it would undermine pre-existing condition protections, increase premiums and destabilize the market," Scott Serota, CEO of Association of Independent Blue Cross Blue Shield Plans, wrote to Senators Cruz and Lee earlier this week.

This story has been updated.