Tough stuff. I think Stephanopoulos is right about how the GOP will spin it — $829 billion over the next decade to insure fewer than 10 percent more of the population? — but this does give The One political cover on his heretofore Big Lie about ObamaCare being “deficit-neutral.” Especially since CBO is the agency that’s been tormenting him for months with projections that the program will cost vastly more than the White House claims. Now, finally, they’ve handed him a politically salable option.

You can read the full 27-page letter at NRO. The money line in the section on budgetary impact: “Those estimates are all subject to substantial uncertainty.” Expect that to be a key GOP talking point given that (a) amendments to Baucus’s bill will wreak havoc with this analysis and (b) Medicare’s initial projection of $12 billion in expenditures for the year 1990 turned out to be “uncertain” too. How uncertain? Actual 1990 expenditures ended up at $107 billion, a cool 800 percent higher than Congress thought they’d be. Woe unto him who relies on any conservative estimate of how much a giant social program will cost.

Even so, I’m troubled by this Red State item posted shortly before the CBO news dropped claiming that Republicans were ready to cave on several key health-care provisions, including the public option(!). That’s implausible, but less implausible now than it was before CBO blessed Baucus’s bill as a deficit-cutter. They’ll never endorse a public option lest the base revolt, but if the White House starts pushing Baucus’s plan as a money-saver, the polls may move and purple-district House Republicans may panic. (Er, are there any purple-district Republicans left? There’s Joe Cao and, um…) Exit question: Whither Waterloo?

Update: The early GOP spin:

Any Democratic response to the CBO report will be “tricky,” says the aide, especially since the Baucus bill is still not defined in legislative language. “Democrats will have to find a way to thread the needle between their promises, the president’s promises, and the reality. The president, Nancy Pelosi, and Harry Reid have said that they wouldn’t add a penny to the deficit. Still, not one poll shows the people believing that. Costs will go up and people aren’t buying the Democrats’ claims.”

“This bill is still the worst of all worlds and the CBO’s report is preliminary,” the aide concludes.

You’ll be hearing the word “preliminary” a lot in the next few days. Meanwhile, Bob Dole puts the GOP on the back and urges them to sign on the dotted line.

Update: Gulp.

The estimate removes a major hurdle toward a vote in the committee, because several senators said they needed to see the cost breakdown before casting a vote – in particular, Sen. Olympia Snowe (R-Maine), who could be the only Republican senator to support the legislation.

A Senate Finance vote is not expected Thursday, but perhaps Friday, Senate aides said.