Donald Trump declared via Twitter last night, “I would not sign Graham-Cassidy if it did not include coverage of pre-existing conditions. It does!”

It doesn’t! It’s probably unrealistic to think the president has spent a meaningful amount of time scrutinizing the details of the legislation he’s eager to sign, but Trump’s assurance is plainly untrue. In fact, there’s no real ambiguity here: the Affordable Care Act guarantees protections for Americans with pre-existing conditions, and the GOP’s Graham-Cassidy plan eliminates that guarantee.

Of course, the president trying to deceive the public about policies he doesn’t understand is, alas, a common occurrence. What’s worth appreciating, however, is that Trump isn’t the only one selling the Republican plan with bogus claims. Yesterday, for example, Sen. Bill Cassidy (R-La.), one of the principal architects of the GOP legislation, said under his plan “more people will have coverage” than under the Affordable Care Act. Is that true? The Washington Post took a closer look:

Cassidy has provided little evidence to support his claim of more coverage, except that innovation would flourish and help bring down costs and expand coverage. That’s certainly possible, but it would be more plausible if his proposal did not slash funding to such an extent. Kimmel’s claim that 30 million fewer Americans will have insurance may be a high-end estimate. But already, in 2019, CBO calculations suggest at least 15 million fewer Americans would have insurance once the individual and employer mandates are repealed. Much of that decline might be by choice, but Cassidy insists the gap will be filled and then exceeded in 10 years. Unlike Cassidy, no prominent health-care analyst is willing to venture a guess on coverage levels – but the consensus is that his funding formula makes his claim all but impossible to achieve.

Vox added that there is “literally no analysis” to bolster Cassidy’s claim. (The Congressional Budget Office could provide lawmakers with a more detailed analysis, but Senate Republicans aren’t prepared to wait until the full CBO score is ready.)

If this were the only tall tale Cassidy and his cohorts were telling, it might seem like a manageable level of mendacity, but it’s actually just the start.

The Huffington Post noted yesterday, for example, the degree to which Cassidy’s office is trying to fool other Senate Republicans with misleading statistics about state-based funding levels in his plan. After Cassidy made the rounds to defend himself against criticisms from talk-show host Jimmy Kimmel, ThinkProgress counted five demonstrable falsehoods.

The New York Times’ David Leonhardt added this morning, “Senator Cassidy, please stop lying about health care.”

Vice President Mike Pence, meanwhile, appeared on Fox News this morning where he made a series of other false claims – and attributed a quote to Thomas Jefferson that Jefferson never actually said.

If the Graham-Cassidy plan were a good idea, why can’t its supporters simply tell the truth about it?