Washington (CNN) This is the point where Republicans in both chambers are staring at the clock and hoping the time to the House and, more importantly, Senate votes ticks away quickly.

Why? GOP aides in both chambers say at this moment, they are well on their way to sending the tax bill to President Donald Trump's desk by Wednesday. But that doesn't mean everyone's on high alert for some late-game problem(s) popping up.

The schedule

The House Rules Committee will meet Monday evening to set up floor consideration Tuesday of the bill.

The House is expected to vote Tuesday.

The Senate is expected to take up the bill soon after, with a final vote Tuesday or Wednesday.

The votes

Sen. Mike Lee: Lee tweeted Monday saying he'd vote for the bill: "Just finished reading the final Tax Cuts and Jobs Act. It will cut taxes for working Utah families. I will proudly vote for it."

Sen. Susan Collins: She formally announced she would vote for the plan Monday afternoon. She also released a statement touting her own "major wins" shortly after the bill was released Friday. All of the deals she made with Majority Leader Mitch McConnell made it into the final bill. The big outstanding questions are the deals she made with McConnell outside of the tax bill -- those related to health care provisions in a year-end spending deal. As of this moment, according to several sources, that deal still stands.

That leaves just one undecided:

Sen. Jeff Flake: Flake hasn't committed to vote for the bill yet, but it's worth noting, the key provision he got into the Senate bill -- a more gradual phaseout of the five-year expensing provision -- is in the final tax deal.

What senior GOP aides are saying: Flake will be a yes.

Do Republican leaders think they're already there on the votes: Yes.

The Corker Kerfuffle

The International Business Times dropped what appeared to be a bombshell Friday about Sen. Bob Corker receiving a specific carve-out in the final bill that would greatly help the Tennessee Republican's own personal wealth in exchange for his flip to "yes" on the bill.

That's not what happened. But the IBT story did identify a change that would specifically benefit real estate businesses -- in a major way -- by including them into the tax cut for so-called "pass-through" businesses.

So where did this change come from? Keep in mind the House and Senate took to very different structural approaches to dealing with pass-throughs.

With that as the basis, the carve-out wasn't "airdropped" in, as has been the accusation -- it's actually an offshoot of the House version of the pass-through language. The basic takeaway is this: any business with depreciable property -- think manufacturing and yes, most definitely real estate, benefits from the carve out.

Bottom line: This wasn't the reason Corker flipped his vote -- he says publicly he wasn't aware, and privately aides directly involved in the process say he had nothing to do with it. But it does underscore one thing that's true throughout the bill: Real estate, and by extension, the President, does very well throughout this legislation.

The Democratic attack line: This isn't going away -- Democrats have seized on the allegations, tagged it with a hashtag (#corkerkickback) and are clearly using it as a -- or the -- key cog in their final attacks against the bill in the next few days. Aides say expect Democratic lawmakers to make a big deal of this in the days ahead.

Corker damage control: Corker is astute enough to know that (A.) this story was gaining traction and (B.) he needed to do something about it. He spoke with leadership policy staffers over the weekend, then proceeded to send a letter to Senate Finance Committee Chairman Orrin Hatch asking for him to lay out the full rationale for the inclusion of the provision into the final bill. He also reiterated he was unaware of its existence until he read about it in news reports.

Just saying: There are a lot of questions about why Corker, who made deficits his reason for voting "no," would flip to "yes" when nothing had been done to address his deficit issue. Of course there are -- it didn't make a lot of sense.

Several aides have made clear McCain's health definitely played a role in why Corker decided to change his vote to "yes." McConnell quietly worked with Corker repeatedly in the days leading up to his switch -- the Tennessee business community, including several close Corker allies and friends, were also vocal in trying to bring him back into the Republican fold. There was a lot of pressure and yes, some changes to the bill that came with it -- but the pass-through carve-out wasn't involved in the discussions.

The gamble: The Republican tax plan is very unpopular at the moment -- The Republican tax plan is very unpopular at the moment -- like historically unpopular for a large legislative effort. Republican leaders brush this off, saying people just don't understand what's actually in it (does that sound familiar?) and in just a few short months, when they look at their paychecks, the tangible benefits of the bill will win them over.

There's truth to the idea that by February, paychecks for millions will look better (how much better? Will it be noticeably better? Still open questions).

But issues like the real estate carve out above underscore the difficulty this bill will forever face -- there are clear winners and losers (as would be the case in any tax bill). Just by the way Republicans structured the bill, many of those winners are on the corporate side or wealthy individual side. That's not only easy to attack for opponents, but it's also something that seems far off-base with the mood of the country that elected President Donald Trump and gave millions of votes to Sen. Bernie Sanders, a Vermont independent, in the Democrat primary.

Just a reminder

What does McCain's absence mean for the tax bill: Barring some major unexpected turn of events, nothing.

To game this out, Republicans have 52 votes in the Senate. Sen. John McCain's absence brings them to 51. They need a simple majority -- not 51 votes, a simple majority of those in attendance at the vote -- to pass the final bill.

So:

If McCain is absent and the above three senators vote yes, Republicans will have 51 "yes" votes. The bill passes.

If Sen. Thad Cochran, who has also been ill, joins McCain in missing the vote, and the above three senators vote for the bill, Republicans have 50 votes and the bill passes.

If McCain is absent, Cochran is in attendance, and say, Collins votes "no," Republicans have 50 votes and the bill passes.

If McCain and Cochran are absent, and one of the above three senators vote "no," Republicans would be in a 49-49 situation -- in which Vice President Mike Pence would cast the tie-breaking vote and the bill passes.

Bottom line: Regardless of the health issues and absence(s), Republicans can still afford to lose another vote and still be able to pass the bill. Aides tell CNN they don't expect to lose another vote -- let alone two, which would sink the bill -- so they think they're in great shape right now.