We all know the stakes — or do we? Plan B is, at base, a messaging ploy designed to convince the public that, if we go over the cliff, it’s because Obama and the damned Democrats wouldn’t take yes for an answer on taxing millionaires. But will the public receive that message?

The latest polling shows that if the country falls over the cliff, 48 percent of Americans will blame GOP leader John Boehner. Only 37 percent said they would blame the president.

“The optics of this favor the president and the Democrats,” Kondik says. “Honestly, how many people are paying attention to Boehner’s ‘Plan B?’ This is a more difficult fight for the Republicans than it is for the president.”

If the PR value is thin, then why’d Boehner do it? Because, for the moment, he can’t get the votes he needs on a deal with Obama:

Republican officials said that members of the GOP leadership had balked at the terms that were emerging. Democrats said Boehner’s abrupt decision to shift to his Plan B — legislation drafted unilaterally by Republicans — reflected a calculation that he lacked support from his own rank and file to win the votes needed for the type of agreement he was negotiating with the president.

That’s from an AP article arguing that there’ll be more negotiations to come after Christmas, although Boehner will obviously have more leverage with Obama if tonight’s bill passes than if it fails. The House has already (barely) passed the companion bill to Plan B this evening, incidentally: The Spending Reduction Act eliminates the automatic defense cuts that were set to take effect on January 1 as part of the sequester. That bill was Boehner’s attempt to sweeten the pot on Plan B for conservatives by giving them some cuts to vote for too. It squeaked through, 215-209. The vote on Plan B itself is scheduled for 7:30 ET but could come a bit sooner or later.

Under normal circumstances, failing to hold the caucus together on a vote on which Boehner’s staked so much might be cause to start looking for a new Speaker. But the rest of the leadership has lined up behind him on this. If it fails, it’s not just his failure, it’s theirs too. Stand by for updates.

Update: Harry Reid’s top flack is milking this for all it’s worth:

House GOP whipping furiously. Can't remember the last time this much effort went into a pointless vote.

— Adam Jentleson 🎈 (@AJentleson) December 20, 2012

Update: Democrats’ new favorite Republican wonders why we can’t all just get along.

Update: Here’s the key number from CNN’s poll today. Plan B is supposed to move these numbers towards the GOP a bit. Emphasis on “supposed to.”

Update: Hmmmmmmmmm:

House GOP calls conference meeting at 7:45 pm et tonight. #fiscalcliff

— Chad Pergram (@ChadPergram) December 21, 2012

Update: Keith Hennessey imagines what a viable fiscal-cliff deal based roughly on Plan B might look like:

I think the following bill could pass the House and Senate before the end of the year.

All tax rates below $700K of income are extended permanently as they are now.
Above $700K, tax rates revert permanently to their pre-2001 rates: 39.6% for income and dividends, 20% for capital gains;
the Personal Exemption Phaseout (PEP) and Pease limit on itemized deductions are not reinstated; and
the AMT is permanently patched.

In addition, I think a separate bill or bills pass to:

extend unemployment insurance in some form;
patch the Medicare “doc fix” for another year; and
delay or mitigate the spending sequester for 6-12 months.

Update: Are they going to pull the bill?

Cantor on whether they would come back and vote tonight: "We'll see, we'll see." #fiscalcliff

— Chad Pergram (@ChadPergram) December 21, 2012

Update: Sure sounds like they’re thinking of pulling the bill:

Rep. Tim Scott (R-S.C.), on his way to see Inouye’s casket, said “I have no clue” what would happen with Plan B — and responded “I have no clue” when asked whether he planned to vote for it…

Rep. Virginia Foxx (R-N.C.), a key Boehner ally, emerged from the Speaker’s office suite carrying a plate of Chick-Fil-A. Asked if she knew whether her conference had the votes to pass the bill, she said, “I have no idea” before rushing away. When she was asked again later as she returned to the office, Foxx grimmaced and kept walking.

Also, Rep. Kay Granger (R-Texas) nodded her head “no” when asked by reporters if she thinks the House will be able to vote and pass Plan B tonight.

Update: Embarrassing:

Cantor says no vote tonight. #fiscalcliff

— Chad Pergram (@ChadPergram) December 21, 2012

Update: The House won’t act further until after Christmas.

Update: Krauthammer, a few hours before the non-vote: “If the ‘Plan B’ does not succeed, if he fails in the House, Boehner has a ‘Plan C.’ That’s the Mayan apocalypse tomorrow.”

Update: War?

Top R source who's anti-Plan B tells me this doesn't threaten Boehner's speakership — but does portend GOP intra-party war.

— Joshua Green (@JoshuaGreen) December 21, 2012

Update: Boehner’s statement:

“The House did not take up the tax measure today because it did not have sufficient support from our members to pass. Now it is up to the president to work with Senator Reid on legislation to avert the fiscal cliff. The House has already passed legislation to stop all of the January 1 tax rate increases and replace the sequester with responsible spending cuts that will begin to address our nation’s crippling debt. The Senate must now act,” he said in a statement.

Update: Brutal:

OH: "Only these Republicans could turn the Bush tax cuts into the 2013 Obama tax cuts."

— Dave Weigel (@daveweigel) December 21, 2012