House Republicans have been working into the nights this week to prepare their signature tax reform bill ahead of its much-hyped release Wednesday. Now that release has been pushed back to Thursday. The problem? Some minor technical issues, like… figuring out what to put in the tax reform bill.

Ways and Means Committee Chairman Kevin Brady, leaving a committee meeting around 9 p.m. Tuesday night, wouldn’t confirm the delay, instead saying that drafters would “work through the night.” In a statement about half an hour later, though, Brady announced that they had decided to delay until Thursday “in consultation with President Trump and our leadership team.”

What could have been holding them back?

Earlier Tuesday evening, Politico had reported that “not 24 hours before the bill’s big reveal, lawmakers had yet to settle on one of the most sensitive questions of all.” By sensitive, they meant: “How to pay for their proposed $5.5 trillion in tax cuts, since any major revenue-generator is certain to antagonize some powerful lobby or group of lawmakers who could defeat it.” Oh yeah. That.

It’s not much of a surprise what most of the difficult issues are. What’s surprising is that, one day ahead of the bill’s scheduled release, they still hadn’t made all of the necessary decisions. From Politico:

But it’s the unresolved issues that are causing Ways and Means members the most heartburn right now. Those include: how to win over GOP lawmakers from high-tax states that are balking over curbing the state and local tax deduction, which their constituents rely on. There are also question about how to ensure wealthy individuals don’t take advantage of the lower 25 percent small business or “pass-through” rate.

Many of the unresolved items are hot-button issues, including what to do with 401(k) retirement plans.

Stray Republican lawmakers still lingering around the House side of the Capitol on Tuesday evening were just as surprised as those reporters huddling outside a Ways and Means Committee meeting room. One lawmaker, New York Rep. Dan Donovan, had the news broken to him by reporters. Another, Ohio Rep. Jim Jordan, said he’d just heard about it during a TV hit with Lou Dobbs.

“That is disappointing,” Jordan, a leader of the conservative House Freedom Caucus, told me. “We supported the Senate budget and didn’t go to conference because this bill would be coming out.”

Leaders hope to have tax reform bills passed out of the House and Senate by Thanksgiving break, in a few weeks.