Senate Republicans held off voting on their tax reform legislation Thursday evening after a few key members balked at its deficit impact, prompting GOP leaders to work on revising the bill in the hopes of passing it Friday.

Senate Majority Leader Mitch McConnell, R-Ky., announced Thursday evening that the next roll call vote would be Friday morning at 11 a.m.

The delay came after Republicans discarded their plan to implement a "debt trigger" for their plan in a Senate floor meeting. After being told that the mechanism would run afoul of Senate rules, they gave up on it and began hashing out other ways to raise hundreds of billions of dollars of revenue to put deficit hawks at ease.

McConnell and leadership are trying to win the votes of Sen. Bob Corker, R-Tenn., and others who had sought the trigger, which would have allowed higher tax rates if federal revenues fell short of projections. Senators said Corker demanded even bigger offsets Thursday night after an official congressional analysis released in the afternoon found that the bill would increase deficits by $1 trillion over 10 years, even after accounting for faster economic growth.

On leaving the Capitol Thursday night, several Republicans said they didn't know what language could be added to appease Corker.

But raising the revenues needed — more than $350 billion — would necessitate major changes to the bill.

"It all becomes a problem," Lindsey Graham, R-S.C., said of the changes to other parts of the bill that would be necessary to raise those funds.

"That means some things may get delayed, there’s all kind of ways to fix this," Graham added. "The one thing you can’t fix is failing."

Corker was said to be working toward a fix with Sen. Pat Toomey, R-Pa. The senators, both members of the Budget Committee, were the two who originally struck a deal to limit the tax cut to $1.5 trillion for the purposes of Senate rules.

Senators mentioned two options Thursday night that were under discussion. One would be for the corporate tax rate to begin rising again after a period of six years or so, increasing from 20 percent by a half percentage point every year. Another would be to schedule in an alternative minimum tax that would hit corporations and high-income earners.

Ted Cruz said he had "serious concerns" with scheduling automatic tax revenue increases. He said he'd rather have spending cuts, or include a "reverse trigger" that lowered taxes on individuals if revenues came in stronger than projected.

Meanwhile, Republicans downplayed the setback encountered Thursday.

"My flight is late tomorrow afternoon," said Lamar Alexander of Tennessee. "I was not planning to leave tonight."

"Some of my colleagues want to make some changes and I respect that," said Louisiana's John Kennedy.

Asked when the actual revised tax bill might be revealed, Kennedy joked: "I just work here. I have no idea."

A crowd of protesters had assembled outside the Capitol in anticipation of Republicans trying to pass the bill late Thursday. As senators left into the night, they faced chants of "kill the bill" and "shame!"

Big questions were still left to be answered Friday. As of Thursday evening, Wisconsin's Ron Johnson was still holding out endorsement of the legislation until after he could offer an amendment expanding the tax cuts accruing to small businesses.

And even apart from any mechanism meant to address debt concerns, several Republicans were planning amendments that would slightly increase the corporate rate to pay for other priorities. Marco Rubio of Florida and Mike Lee of Utah were looking for a vote to expand child tax credits to more low-income families using those revenues, while Susan Collins of Maine wanted to add a deduction for state and local property taxes.