Paul Kane, who covers Congress and politics for The Washington Post, is legendary inside our newsroom for sending smart emails around about what’s coming down the pike on the Hill. He’s been fully immersed in the trade battle for months. Late Wednesday night, when he was off deadline, we mind-melded with PK, as he’s known around town, about what to expect in the next 36 hours.

What exactly does the Friday vote accomplish?

Assuming the White House and House GOP leaders are confident they can win, they’ll have a series of votes Friday to advance Obama’s trade agenda. The main event is TPA, Trade Promotion Authority, which sets the table for the president to finish the 12-nation trade deal with Pacific-Rim nations. He says he needs this authority because the final details cannot be worked out of the Trans Pacific Partnership until the other nations know that Obama can submit the deal for congressional approval without any amending it or altering in any fashion. It goes along with there not being 535 commanders in chief on foreign policy, advocates say, that there can’t be 535 negotiators in chief on trade. But Congress gets a long review process, under TPA authority, and there would be up-or-down votes to affirm the trade deals. Just because TPA passes does not mean TPP is a foregone conclusion.

But, if TPA fails, TPP is toast. Which is why labor activists and other opponents of the deal are putting so much effort into defeating TPA, a way to effectively crush Obama’s trade agenda in a single fell swoop.

Does Obama have the votes to get this done?

Ah, the $64,000 question.

Your back-of-the-envelope math: there are 246 Republicans, 188 Democrats and one vacancy. The magic number is 218. Anything led by Paul Ryan, whose standing inside the GOP caucus is as strong as it’s ever been, has almost always been certain to get 2/3 of the House Republican Conference, and that puts you at 165 votes for starters. Ryan just has that much goodwill, and he’s been the main weapon supporting this.

The normal bloc of 50-ish Republicans who want to be against anything Obama is for, are a problem, but some of them – think Reps. Matt Salmon (R-Ariz.) and Tom McClintock (R-Calif.) – are vocal TPA supporters. That helps. The most troubling bloc is several dozen who aren’t normally troublesome but come from Midwestern districts where job losses in manufacturing have been heavy. Supporting trade is not easy for them. Still, Ryan and GOP leaders believe they can hit their mark of 190 to 200 Republican votes.

That leaves Democrats to fill the gap. Leadership, both Nancy Pelosi and Steny Hoyer, have been completely silent on the issue and their advisers say that, given the antipathy toward this legislation among rank-and-file, public silence is the best the West Wing can get. There are roughly 20 public yes votes among Democrats, and Obama will need at least five to 10 more in order to go ahead with the vote Friday.

How much arm twisting is going on? 

Rep. Gerry Connolly (Va.), one of the most public Democratic supporters of TPA, says his side is going with a “light touch” approach – lots of phone calls, even with Obama if needed; meetings with cabinet officials; more phone calls; reassurances of political support from if Democrats face labor-backed primary opponents. He says that’s a strong contrast to unions and their congressional backers, who are making political threats of primary challengers. “It’s a pretty hard sell,” Connolly says of the other side.

But this is unlike past trade deals. People aren’t giving away bridge funding or new VA hospitals to win votes. Republicans have given relatively small policy inclusions in side bills. Rep. Steve King (R-Iowa), the most vocal opponent of illegal immigration, got language in a side bill that says these trade deals can’t be used to force more immigration into the U.S. Leadership was fine doing that – because it’s a trade deal and they see no way it will turn into an immigration treaty, and they got King’s vote in exchange for language that, they think, doesn’t mean that much.

Are Republicans using procedural gimmicks to ensure passage?

The process allows two votes – one on the fast-track authority for trade, the other on the companion Trade Adjustment Assistance (TAA), providing funding for worker training programs for those that lose their jobs because of global competition. If both pass, they will magically re-attach and get sent to the White House for Obama’s signature of one bill. It sounds really odd, but Pelosi did this all the time as speaker: Republicans and a few dozen Democrats would support war funding, and then Democrats and a few dozen Republicans would also support domestic emergency funds for crises such as hurricane and drought relief. Both would pass and go to George W. Bush’s desk for his signature.

This time, Boehner needs all Democrats and a few dozen Republicans to support TAA (which many conservatives oppose as a form of welfare), and then most of his Republican caucus and a few dozen Democrats to support TPA.

What will become of TAA?

That’s potentially the biggest hurdle. By splitting the votes, Boehner has effectively empowered the Democratic opponents to Obama’s trade agenda. He needs them to vote for TAA, or else TPA fails. So Reps. Rosa DeLauro (D-Conn.), Jan Schakowsky (D-Ill.) and their cohorts leading the anti-TPA charge have highlighted how the increased TAA funds have a pay-for that is a slight cut to Medicare in 2024, which Democrats say is anathema to the party that defends entitlements.

Ryan worked with Democrats to come up with a different pay-for: tighter tax enforcement, which could kind of be construed as a tax increase, a win for them. But right now Boehner doesn’t want to alter the TPA or TAA language, he just wants to pass those as written and send them to Obama, so this doesn’t have to go back to the Senate for re-consideration. He’s included the new pay-for in separate, non-controversial legislation involving trade with Africa, which Senate GOP leaders have pledged to quickly pass. So, no problem, right?

Not so. The anti-trade Democrats say that they will not vote for the TAA bill as long as that language saying there’s a cut to Medicare is in there, no matter if there will be a superseding law that passes and makes it irrelevant. They don’t trust Republicans or their outside super PAC allies, saying they’ll still face attack ads from them for “cutting Medicare.” As of late Wednesday, Pelosi’s official position was to support that faction, and as our good friend Jake Sherman noted in the late afternoon, the top Obama advisers from the West Wing – led by Chief of Staff Denis McDonough – huddled with her to try to find resolution.

Who are two or three key people to watch ahead of the Friday vote?

On the Democratic side, keep an eye out for the Congressional Black Caucus, where appeals have been made that Obama is being unfairly denied a trade negotiating right that every post-World War II president has had. A handful of CBC members could emerge and make the difference. Additionally, watch Rep. Debbie Wasserman Schultz (D-Fla.). She is Obama’s Democratic National Committee chairman and yet she’s undecided. She’s ambitious and wants to climb the internal House leadership ladder, which tilts toward voting no, and her relationship with the West Wing and Obama’s top political advisers has been severely damaged by a 2014 report in Politico that was based on anonymous criticism of her from Obama’s allies.

On the Republican side, keep an eye on some veterans from Texas, such as Reps. Michael Burgess and Kay Granger. They aren’t usually problems for the GOP leaders, but they’re from deep red districts where doing anything that gives “authority” to Obama is not the most prudent thing to do.