Updated

"Obama and Leaders Reach Debt Deal," hailed the New York Times."White House, Congressional leaders reach deal," said the Washington Post."Debt deal: Obama, Hill leaders break through," proclaimed Politico.

President Obama on one side of the table. Bipartisan Congressional leaders on the other.

But even though those sides conducted most of the negotiating, they represent a small percentage of the legislative apparatus that will be asked to approve this package in the next two days.

After weeks of talks, charade votes, heated barbs and exceptional brinksmanship, finishing the deal will come down to mathematics.

It's simple, really: 60 votes to clear a filibuster in the Senate and then 51 for final passage. And in the House, the magic number for this exercise is 216.

To start, let's look at the House where the legislative lift could prove most challenging.

As of this writing, it's unclear which chamber might try to move the bill first. The measure is potentially loaded up, ready to go in the Senate, riding along in the skeleton of an old bill crafted to modernize the Freedom of Information Act. This piece of legislation already carries extraordinary privileges, skipping toward the front of the parliamentary line and vaulting at least one potential filibuster.

But Congressional leaders face a looming deadline of Tuesday night. So it's likely Congressional leaders will choose the easiest course that assures passage of the bill in both chambers.

And starting in the Senate might be best under that logic.

Here's why: the peripheries of both parties, liberal Democrats and tea party Republicans abhor this bill. It's unlikely that many of those lawmakers at the margins can support it. That makes it challenging to cobble together a coalition of Democrats and Republicans. But that said, the bill seemingly has more backing in the Senate than it does in the House.

A good example of that broad Senate support comes from Sen. Jay Rockefeller (D-WV). In a statement late Sunday, Rockefeller decreed the bill "a reasonable compromise" and said he was ready to vote for it.

However, other left-leaning lawmakers like Sen. Bernie Sanders (I-VT) won't back it at all.Sanders decried the deal as "grotesquely immoral." But picking up support from the likes of Rockefeller is crucial because if the legislation passes the Senate, it drastically improves its chances in the House of Representatives.

It's widely believed that Democratic Congressional leaders in both the House and Senate made a near-fatal tactical error with the infamous TARP bailout bill in the fall of 2008. It was clear from the beginning that TARP enjoyed overwhelming Senate backing. But leaders elected to move it through the House first. It failed in a catastrophic vote which precipitated the single-biggest one-day point slide in the history of the Dow Jones Industrial Average.

Still, the Senate took up the bill a few days later and passed it 74-25. Both candidates Barack Obama and John McCain even flew back from the presidential campaign trail to cast aye votes.

The bill then returned to the House and passed there.

This phenomenon is what I'll call the "Mikey Method" of passing legislation.

Many recall the iconic 1970s Life cereal commercials, featuring Mikey. Two brothers sit around, shoving a bowl of cereal back and forth, each refusing to try it. They finally shove the bowl in front of Mikey who begins to inhale it. The brothers then realize that Life is tasty and they want a bowl, too.

In the case of TARP, the House wasn't ready to try the cereal. So the vote disintegrated. But once the Senate gobbled it up, the House was more than happy to devour a bowl of TARP.

For the same reasons, expect astute vote counters to consider originating the debt ceiling package in the Senate and then send it to the House. Passage of any legislation by one body always bolsters its chances in the other. Plus, yea votes could give skeptical representatives cover if both of their state's senators vote yea.

Regardless, this House vote could prove to be a challenge.

At first blush, many lawmakers interpreted this deal to mirror the initial debt limit bill propounded last week by House Speaker John Boehner (R-OH). Of course, such a description can't sit well with rank-and-file Republicans who balked at the first iteration of the bill last Tuesday. They then forced House leaders to yank the legislation from the floor Thursday night when it was apparent they lacked the votes.

That said, buy-in from both Boehner and House Minority Leader Nancy Pelosi (D-CA) will prove crucial to mix just the right cocktail of Republican and Democratic votes to advance it to passage.

"Now listen, this isn't the greatest deal in the world," said Boehner on a Sunday night conference call with rank-and-file GOPers. "But it shows how much we've changed the terms of the debate in this town."

On the call, House Budget Committee Chairman Paul Ryan (R-WI) told his colleagues the baseline spending number is better in this legislation.

Still, many tea party loyalists are upset that the package doesn't require a balanced budget amendment prior to a debt ceiling hike. Secondly, many hawkish Republicans are concerned about how cuts down the road could imperil the military.

Pro-defense Republicans were already on watch Saturday, criticizing one debt ceiling plan authored by Senate Majority Leader Harry Reid (D-NV).

"Our commitment to men and women in uniform should not be a political number based on votes," said Defense Appropriations Subcommittee Chairman Bill Young (R-FL). "It should be based on threats and what the U.S. needs to do for security."

By Sunday afternoon, it was apparent substantial numbers of House Republicans would defect.

Republicans already had trouble marshaling the votes for a revamped version of Boehner's plan Friday night. Twenty-two House Republicans voted no on that measure. With 240 Republicans serving in the House, the GOP can only lose 23 of its own before it needs to rely on help from across the aisle to pass legislation.

No Democrats voted for Friday's package. So to ensure passage of Boehner's plan, the GOP whip operation had a handful of "in case of emergency, break glass" votes at its disposal.

Reps. Tim Scott (R-SC), Trey Gowdy (R-SC) and Tom Latham (R-IA) were a few of those votes.

During the tally, House Majority Whip Kevin McCarthy (R-CA) patrolled the center aisle, standing right next to Scott and Gowdy, who reclined on the Democratic side of the chamber. Both were reluctant to support the bill. But as the clock ticked down to 00:00, neither bothered to vote. Once it was apparent the House had the necessary votes, McCarthy "released" Scott and Gowdy who voted nay.

Latham, who is one of Boehner's closest friends in the House and often dines with him in suburban Virginia, was undecided earlier in the week. Due to redistricting, Iowa loses a Congressional seat next cycle. So Latham finds himself running against Rep. Leonard Boswell (D-IA) next year. Latham may have been hard-pressed to vote against his friend if Boehner really needed the vote. But Latham waited on the sideline until the end. He voted nay a nanosecond before the gavel came down, closing the vote.In other words, if the GOP had to go to such lengths to approve that package, how tough will it be to assemble the necessary votes for this bill?

Here's where Democrats may come into play.

And some aren't too impressed.

Rep. Raul Grijalva (D-AZ) chairs the Congressional Progressive Caucus. He blitzed the new measure Sunday with a seething statement.

"This deal is a cure as bad as the disease," Grijalva said, adding that leaders conjured up the bill just to appease "right-wing radicals."

But Grijalva's statement was not nearly as blistering as the description used by Congressional Black Caucus Chairman Emanuel Cleaver (D-MO).

Any sandwich shop worth its provolone could make a Dagwood, a Hero or a Sloppy Joe.

But Cleaver took sandwich artistry to an entirely new level over the weekend. As in Dante's levels of Hell, likening the deal to a "sugar-coated Satan sandwich."

One presumes that comes flame-broiled.

And it's unclear if you get cole slaw or a pickle on the side.

So such stark opposition from House Democrats could spell trouble for the legislation if Republicans need the votes.

Nancy Pelosi huddled with her inner-circle and Reid for several hours Sunday afternoon. She emerged to declare that there could be a chasm between House Democrats and Mr. Obama.

"We may all be able to support it or none of us may be able to," Pelosi said.

A few hours later, the leader indicated she would review "the legislation with my caucus to see what level of support we can provide."

"Can provide" is an interesting choice of words for a master vote counter like Pelosi. As House Speaker, she personally whipped the votes for the health care bill in 2010 and the cap and trade/climate package in 2009.

But, as indicated at the outset, the debt limit vote is about numbers. It always has been. And here's how this deal could still collapse.

216 is what's needed to pass something in the House. There are currently two vacancies and Rep. Gabrielle Giffords (D-AZ) and Maurice Hinchey (D-NY) aren't voting. due to health issues. Republicans boast 240 members in their conference. It's believed Boehner will live by the "Hastert rule," named after former House Speaker Denny Hastert (R-IL). Hastert always required a "majority of the majority" to favor legislation before he'd allow it on the floor.

But with unconvinced tea party members and skittish defense hawks, this could create trouble for the GOP. It can only lose 119 of their own before needing Democratic backup to reach 216. That means Republicans could be searching for up to 95 Democratic yeas.

Various Capitol Hill sources signaled that Democrats won't have to deliver that many votes. It's believed that Boehner could deliver around 150 Republicans, meaning Democrats would have to cough up 66 of their own.

That's a tall order. Especially for a piece of legislation no one truly embraces.

This is what happened with the TARP bailout vote in September, 2008. Democrats and Republicans needed to cobble together a coalition of members to vote for a toxic piece of legislation that no one truly wanted to support. Democrats didn't require some of their safe lawmakers to vote yes and Republicans didn't offer anywhere near the number of votes anticipated by the Democratic whip operation. So the vote melted down. And a few moments later, the market followed suit.

This is the risk of failure Republicans and Democrats face on the floor. There are remarkable parallels to the TARP vote. And at the end of the day, it's not about the "deal" the president cut with leaders from both chambers. It's about getting the votes from rank and file members.

That's why Congress struggled for months to find a solution to the debt crisis. The votes have never been there.

And we'll know soon if they're there now.