President Trump and other Republican leaders all insist that the latest effort to repeal Obamacare will protect those with pre-existing conditions.

"I would not sign Graham-Cassidy if it did not include coverage of pre-existing conditions. It does! A great Bill. Repeal & Replace," Trump tweeted Wednesday night about the legislation authored by Senators Lindsey Graham and Bill Cassidy.

Is that true?

No. It does not provide the same sweeping protections of those with pre-existing conditions as Obamacare.

Here's why:

Prior to Obamacare, many people with pre-existing conditions found themselves branded uninsurable for life on the individual market. Even a bad case of acne as a teen made it hard to get coverage.

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Insurance companies routinely turned people with pre-existing conditions away or charged them sky-high premiums. Today, more than a quarter of non-elderly adults have health conditions that would have made them ineligible for coverage in this market, according to the Kaiser Family Foundation.

Those with employer policies fared better, but even there, it was possible to get hit. Health care bills were one of the leading causes of bankruptcy.

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The Affordable Care Act changed all that. Insurers are no longer allowed to turn people away, nor charge them more, because of a pre-existing condition. Period.

Plus, carriers must offer comprehensive policies that cover a wide array of treatments and medication.

I would not sign Graham-Cassidy if it did not include coverage of pre-existing conditions. It does! A great Bill. Repeal & Replace. — Donald J. Trump (@realDonaldTrump) September 20, 2017

Here's what the latest Obamacare repeal bill would really do:

Just as in Obamacare, insurers could not turn away those with pre-existing conditions. But it would leave it up to the states whether to continue other protections.

States could opt to once again allow carriers to base premiums on a person's medical history and to sell skimpier policies that don't cover Obamacare's 10 essential health benefits. This would apply not only to the individual market, but to those who get coverage from small business employers.

Also, insurers would be able to cap the amount they would pay for treatment outside of what their states deem an essential health benefit.

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States must describe how they intend to "maintain access to adequate and affordable health insurance" for those with pre-existing conditions. But most experts say this is a very weak standard and there's no mechanism for ensuring states carry this out. Plus, the health secretary "shall waive" these Obamacare provisions if a state applies to change them, meaning there won't be any review on the federal level.

So those with pre-existing conditions could find themselves unable to afford insurance or to only buy bare bones policies that don't cover the treatments they need.

A wide array of doctor and hospital groups, as well as patient advocacy organizations, have come out against the bill. One of their top concerns: It would hurt people with pre-existing conditions.

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James Madara, CEO of the American Medical Association, sums it up in a letter to Senate leaders.

"The Graham-Cassidy Amendment ... violates the precept of "first do no harm," he wrote.