Is this the day that the Supreme Court announces its decision in the King v. Burwell decision?  Many longtime court watchers think it may be.  The challenge to Obamacare subsidies has been the most talked about case of the last couple of years and even experienced nose counters are loath to predict which side the court will come down on.

The Hill:

On opinion days, dozens of reporters are packing into the court or swarming the steps outside, while nearly 10,000 people tune into SCOTUSblog for live updates. False reports attempting to predict the timing of the decision have only further fueled the hype.

Across Capitol Hill, Republicans in the House and Senate briefed their members for the first time on Wednesday, trying to calm fears about what could happen to the 6.4 million people whose ObamaCare subsidies are at stake in the case. 

Some of K Street’s biggest lobby firms are drafting “pre-decision” memos and briefing clients even outside of the healthcare realm about how they could be hit by a ruling. 

Democrats are also getting nervous. 

On the same afternoon as the Republican meetings, Health and Human Services Secretary Sylvia Mathews Burwell privately met with members of the New Democrats Coalition on Wednesday to talk about the case.

"In my state of Georgia, 500,000 people would lose their insurance — 8 or 9 million people across the country. And all [states] have to do is put the exchanges in place,” Rep. David Scott (D-Ga.) said as he left the closed-door meeting.

A spokeswoman for the coalition’s chairman, Rep. Ron Kind (D-Wis.), said she couldn’t discuss details, but confirmed the administration’s response to the case was the “main topic of discussion.” 

The growing anticipation surrounding King v. Burwell exploded shortly after midnight Wednesday, when news first  GOP leaders would begin briefing rank-and-file members about the case. 

The meetings took place in separate corners of the Capitol a few hours apart, and both drew unusually large scrums of reporters. 

Facing a barrage of questions after the Senate’s lunch-time discussion, Sen. John Barrasso (R-Wyo..) allowed a half-dozen reporters to cram into his elevator, where Sen. Ted Cruz (R-Texas) had already stepped inside.

“Easy, easy,” Cruz said as he was backed into the corner.

Speculation on who might be the swing vote has centered on Justice Kennedy and Chief Justice Roberts.  Kennedy may wish to use the decision to further his federalist views, while Roberts may have his eye on history and contemporary media.  If either justice jumps, Obamacare will be saved.

If not, the GOP gave its members a look at what they are planning if the subsidies are ruled illegal.  Many members are unhappy with the plan, which doesn't bode well for passage.  Besides, even if the GOP hopped on board, if the plan calls for repeal of the individual and business mandates, President Obama will probably veto it.

So buckle up, and strap it down.  It's going to be a wild ride to the Obamacare finish line.