(Bloomberg) -- Republican Senator Bill Cassidy is making anoffer to Democrats he hopes they won’t refuse: If their states likeObamacare, they can keep it.

A doctor who worked for decades in charity hospitals and clinicsbefore joining Congress, Cassidy plans to introduce soon an updatedversion of his health-care plan aimed at giving states flexibilityto keep Obamacare, aka the Affordable Care Act, nix it entirely ortransition to a new system of health savings accounts and automatichealth plan enrollment.

"You can go to the reddest state and say we have the option toroot and branch it, and you can go to the bluest state and say wehave the option to keep what we like," the Louisiana Republicansaid. Under his plan, "Republicans say, ‘You have the option tokeep your plan,’ and we mean it," he added.

Republicans will need Democratic support to pass a full replacement for Obamacare, and Cassidy’sapproach may be the most likely to appeal to Democrats of the onesoffered by the GOP so far.

Related: See all our ACA coverage

"We should have a plan that isn’t Republican, that isn’tDemocrat," he said. "Our plan gives each state the authority to runthe health plan in their state as is suitable to their peculiarsituation, and that’s hard to argue with unless you want more powerin Washington, D.C."

"A reasonable person can say, I live in California, I loveObamacare, this plan allows me to keep it. And I live in Arizona,my premiums just went up 100 percent and I have a chance to dosomething different."

Related: Rand Paul is drafting his own ACAreplacement

That’s a feature that other proposed replacement plans floatingaround -- like that of Representative Tom Price of Georgia,nominated to be secretary of Health and Human Services -- don’thave.

Defining ’repeal’

Notably, Cassidy has a narrow view of what would count as"repeal" of the 2010 Affordable Care Act.

He wouldn’t touch the changes it made to Medicare, nor would heeliminate the Medicaid expansion or the law’s taxes, at least notright away. But the federal mandates, which Cassidy said are whathis constituents popularly think of as Obamacare, would goaway.

Related: ACA repeal would put budget in the red by$350 billion

"They are concerned about the penalties, the mandates, therequirement to buy things they don’t need and therefore theescalating costs. If we address that, we’ve repealed Obamacare,"Cassidy said in an interview. "They just hate the federalgovernment telling them how to live their lives."

There are roadblocks ahead, especially because he wants hisfellow Republicans to delay repealing the law’s assorted tax hikesuntil they can be replaced as part of a broader tax overhaul laterthis year.

Cassidy had the backing of Republican leaders Mitch McConnelland John Cornyn for an earlier bill in 2015, when they thought theSupreme Court was set to invalidate subsidies in many states in theKing v. Burwell case; the court upheld those subsidies. Now,leaders haven’t indicated which plan they will back, and Cassidy isstill revising his bill.

Cassidy said he doesn’t see how Republicans can repeal all ofthe taxes now and have a robust alternative later that could insuremore people than the Affordable Care Act without adding to thedeficit -- because Republicans wouldn’t vote to raise taxeslater.

"Terrible problem! You can’t do it!" he said.

CBO trouble

The Congressional Budget Office, meanwhile, weighed in Tuesdaywith an ugly new assessment of last year’s GOP repeal bill, whichObama vetoed. The CBO estimated 18 million people would have lostcoverage in the first year of implementation and premiums wouldhave risen an extra 20 to 25 percent, provided that consumerprotections like a ban on refusing coverage to people withpre-existing conditions stayed on the books.

After a decade, the CBO predicted virtually the entire non-groupmarket would have failed, with insurers abandoning it, premiumsdoubling and 32 million more people without coverage than ifObamacare had continued.

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Republicans were quick to pronounce the score "meaningless"because they will have a replacement, but the stark numbersunderscore that they have yet to agree on one.

Cassidy has worked on his bill with fellow Republicans,including Senator Susan Collins of Maine and House Rules ChairmanPete Sessions of Texas, among others.

He said he doesn’t expect Democratic support up front -- hethinks the first bill aimed at setting an expiration date forObamacare will be too partisan for Democrats to considernegotiating. In addition, Democrats still hope the repeal effortwill falter.

‘Have our act together’

"We have to show that we have our act together before they’regoing to risk it, I get that," Cassidy said. He has spoken toseveral Democrats, and hopes they’ll consider working with the GOPon a follow-on "replace" bill rather than get left out of theprocess entirely.

A key feature of Cassidy’s plan is a provision allowing statesto automatically enroll eligible people in health plans unless theyopt out. Cassidy said this could get more people insured thanObamacare’s approach of taxing people who fail to get insurance,citing studies showing people are far more likely to participate inbenefits like 401(k) retirement savings plans under such an opt-outmodel.

His plan aims to solve the dilemma Republicans face over nixingthe Medicaid expansion. The party faces a split between senatorsfrom states that are getting billions of federal dollars under theexpansion and senators whose states rejected it. Republicans can’tdo anything without the votes of both groups of senators, giventheir slim 52-48 majority.

Cassidy would let the money keep flowing, but with far fewerstrings attached. States that didn’t expand Medicaid would getfresh funding based on how many people they insured. The newspending in those red states wouldn’t count as increasing thedeficit because the CBO assumes those states will eventually expandMedicaid and take the money, Cassidy said.

He said he envisions a multi-year transition to his plan -- anew law this year, a year for states to decide which option tochoose, and implementation in 2019.

Cassidy, like Price, also includes in his plan refundable taxcredits that he envisions going into health savings accounts.

Price’s plan could have a leg up initially given his key role inthe administration. But Democrats, unions and their allies arelikely to to attack it heartily, including his intention to limitthe tax deductibility of employer-provided health insurance, wheremost Americans get their coverage. To help pay for a new system oftax credits, he would limit employer-provided tax-deductible healthcare to $8,000 a person and $20,000 for a family plan.

Public 0utcry

Already there are signs of a public outcry from constituentsworried they will lose their insurance, and Cassidy said peopleshould weigh in with Congress if they want to keep parts ofObamacare they like.

"If they want to continue to have pre-existing conditionscovered, they need to let their representative know," he said.

"If they want to continue to have some help to purchase coveragefor those who are lower income or those who are otherwisestruggling, they need to let us know," he added. "I think they do,when I speak to them, but I’d like to think that we’re trulyfunctioning as representatives, not as like Obamacare turned out tobe: ‘Whether you like it or not, suck it up, you’re gettingit.’"

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