Back on November 3rd, Eric Levitz of New York magazine took a look at what some Republican senators had already said on the record and concluded that “it’s hard to see how the Tax Cuts and Jobs Act ever becomes law.” His focus at that time was on Sens. Bob Corker of Tennessee, Susan Collins of Maine, and John McCain of Arizona. He didn’t mention Senator Ron Johnson of Wisconsin who has since come out strongly against the bill.

Each of these senators have expressed slightly different concerns. John McCain is reluctant to support the process that is being used since it doesn’t follow “regular order.” This basically means that the bill is being negotiated behind closed doors without expert testimony and open hearings. The opportunity to offer amendments will be limited, as will be the time to debate the bill on the Senate floor. For McCain, this isn’t how Congress should operate and it was the primary objection he had to the effort to repeal Obamacare.

Sen. Corker is more concerned about adding to our national debt, and he’s promised not to vote for a bill that hurts the nation’s bottom line. Unless he goes back on this promise, he’s going to be a ‘no’ vote.

Sen. Collins doesn’t like the repeal of Obamacare’s individual mandate that has been added to the bill and has said that she doesn’t support it. She also objects to a repeal of the Estate Tax.

Sen. Johnson complains that the bill “is imbalanced in favor of large corporations.” Like McCain, he also has big problems with the process.

So far, only Johnson has definitively stated that he won’t vote for the bill, but the objections of the others have either not been addressed or addressed halfheartedly.

On the House side, the omens look good for the Republican leadership, and they’re expected to pass their version of the tax bill later today. This time, they’re not expected to do a victory lap in the White House Rose Garden like they did back when they passed their Obamacare repeal. That’s because they now realize that there is no victory until the Senate can produce.

Senate Majority Leaders is under tremendous pressure and he won’t want to see the process die in his chamber again. But he can only lose two votes and he’s got more than two problem senators. If he can’t figure things out quickly, and the Republicans lose the special election in Alabama on December 12th, he’ll be in even a tighter jam.

If you’re gaming this out at home, you should also remember that eventually the House and Senate will have to agree to a single bill, so there are some tradeoffs that won’t ultimately work because even though they’d make passage in the Senate possible, they’d ruin the chances of passing it through the House. But McConnell would very much like failure, if it comes, to come in the conference committee negotiations with the House so that blame can be shared.

In any case, if the House passes their bill today, as expected, that’s an important hurdle cleared. But it isn’t assurance of anything.