Washington (CNN) After more than seven years of campaign pledges -- and 42 days since their initial effort failed in epic fashion -- House Republicans now say they have the votes to repeal and replace the Affordable Care Act.

Here's what to watch Thursday and how they got to this point.

Do they actually have the votes?

House Majority Leader Kevin McCarthy explicitly says yes. House leaders have made crystal clear nothing would be scheduled for a floor vote until they had 216 votes. So do they have 216 votes? Well, here's a sampling of GOP aides after the announcement last night.

"Close enough to go."

"Buckle up."

"Still have some work to do, but we're there."

Here's the reality: In situations like this, in votes this close, leadership relies heavily on members who make clear they'd really rather not vote for this bill, but they'll be there if leaders need them. By all accounts, on Thursday, leaders are going to need them.

So while Republicans aren't going into this vote with 216 firm, happy, "yes" votes, they have a handful of members who have given commitments that they'll be there if they need them. And that, based on the decision to green light the vote Wednesday night, makes them comfortable enough.

Why are they voting now, without an updated Congressional Budget Office score, less than 24 hours after the final amendment text was posted?

Because they think they have the votes, and when you have the votes, you vote.

Pretty good adage to go by on Capitol Hill: plan beats no plan, votes beat no votes.

Translation: no matter how flawed, something officially on paper, in legislative text, will win the day over some amorphous perfect policy proposal. Similarly, something that can get 216 votes beats something that can't.

Seems obvious, but that's really the explanation. House leaders are keenly aware that the longer this hangs out there, the less likely it is they'll gain votes. In fact, as interest groups, town halls, the opposition gets a hold of things, it's more likely they'd hemorrhage them. So despite not knowing how many people this updated plan would cover, or how much it would cost (or, in this case, cut from the deficit), they're going to the floor. Votes beats no votes.

Was an $8 billion cash infusion the silver bullet?

On the policy? No. While GOP policy staff says explicitly they believe the $8 billion added to the bill Wednesday is enough to address any concerns raised by states opting out of Obamacare's pre-existing conditions price protections, there are no shortage of policy analysts and Democrats who vigorously dispute that.

But on the momentum? Without question. It's tough to overstate what flipping, in such a public way at the White House, Reps. Billy Long and Fred Upton did for the prospects of this bill. Leadership had run into a brick wall. They weren't going to get the votes. They were staring 2.0 (or 3.0?) in the face. Flipping two very high profile "no" votes, and doing so with a proposal that ostensibly addresses the core of the concerns that have plagued the new proposal up to that point (giving states the ability to opt out of the price protections in Obamacare), was a very big deal.

JUST WATCHED Spicer responds to Kimmel's monologue Replay More Videos ... MUST WATCH Spicer responds to Kimmel's monologue 00:58

It gave leaders something to take to their undecided members. It showed momentum. It gave the appearance that the train was moving and it was time to get on board. It forced the hands of moderates who were keeping their powder dry. It got them to a vote.

"It gave our guys a clear-cut reason to get to yes," one senior GOP aide told CNN.

What was the final calculation of members on this?

It's not homogenous, but for several dozen or so members over the past two days, it essentially comes down to this: the price of doing nothing outweighs the price of doing something that could be politically very unpopular.

This has, believe it or not, long been the argument leaders have made to their members: you campaigned on this. All of you. You can't just not do something. Up to Wednesday, that wasn't enough. But it was clear there were plenty of members looking for a reason to get to yes, somehow. The Upton amendment got them there.

Also, and the importance of this cannot be understated: they're tired. Members (and leaders) are ready to move on. This has been an albatross on the conference for nearly months. It's time for the Senate to deal with this hot potato. It's time to get to the next portions of their agenda. (And it's time to go home for an 11-day recess.)

What do Democrats think about this process, and the policy behind it?

"Everything about this bill, everything about this is a political ad maker's dream," one top Democratic ad maker told CNN.

But this is dead in the Senate, right?

Making premature proclamations of what lives or dies in Mitch McConnell's Senate is a bit of a dangerous exercise.

Here's the reality: there are no shortage of Senate Republicans who weren't angry the House had come up short up to this point. The process had become a political and policy nightmare, one many were more than happy to avoid.

But should the House get this done Thursday, it's now on the Senate's plate and there is every expectation Republicans will move on it.

JUST WATCHED Trump talks health care and Mideast peace Replay More Videos ... MUST WATCH Trump talks health care and Mideast peace 02:33

Just expect it to look very, very different by the time it's all said and done. House and Senate leaders believe many of the proposed changes to the Obamacare insurance regulations would be stripped out altogether by Senate rules. The structure of the tax credits. The shape of the Medicaid expansion provisions. The future of the infrastructure of Obamacare. The defunding of Planned Parenthood.

These are all issues that will have to be addressed -- and don't have a clear pathway to resolution.

There have been ongoing, behind-the-scenes conversations between several high-profile senators on opposite sides of the GOP's ideological spectrum to try and set the stage for what comes next. But even those involved don't have a great sense of how long it will take to get something done -- if they can at all.

How can I watch the vote?

JUST WATCHED Can GOP holdouts be convinced to support plan? Replay More Videos ... MUST WATCH Can GOP holdouts be convinced to support plan? 05:56

Ideally from inside the House chamber, where there will likely be a couple dozen moderate Republican members standing, waiting, staring at the overall vote tally and just hoping they don't have to vote "yes" on this bill. Watch them, and watch how leaders work them and decide who is free to vote "no" and who has to walk the plank on this.

Keep an eye on how long the vote is open. How long the vote stands just below the gold 216 mark. And, if by chance leaders push it a few votes above the necessary 216 votes, keep a close eye to see if any members flip their votes back to "no."

Who, specifically, should I watch?

There are plenty of lists out there of undecided members, or those leaning "no," and those will all be worth keeping an eye on. But the key is (and frankly, has always been throughout the last two weeks), Rep. Patrick McHenry. He's the chief deputy whip and is a manic, if absurdly patient, worker of votes. Watch where he goes and who he talks to. That's the key on who might be wavering, who they need to vote "yes" immediately, and perhaps, who has just been freed to vote "no."

How it will all go down?

Quicker than normal. Keep in mind, the vast majority of the debate on the GOP repeal and replace plan already happened -- on March 24. Even though leaders had to pull the bill from the floor, the debate on the bill itself had been ongoing all day up to that point. So this will move fast.

And it will also entail a vote on a second bill -- a separate proposal to remove the politically toxic exemption for members of Congress and their staff from the effects of any opt-out of Obamacare's insurance regulations. It was a provision that was put into the bill in order to be compliant with Senate rules. As such, it's still in there. This separate bill will be a standalone effort to remedy that.