Senate Republicans rushed to patch up their tax bill Thursday only hours before an expected vote.
The Senate parliamentarian ruled Thursday that a fiscal "trigger," important to winning deficit-wary Sen. Bob Corker's support for the GOP plan, will not work under Senate rules. Republican senators are now looking to find new ways to address the concerns of Corker, a so-called deficit hawk Republican from Tennessee.
"It doesn't look like the trigger is going to work, according to the parliamentarian," Cornyn told reporters, according to Politico. "So we have an alternative, frankly: a tax increase we don't want to do to try to address Sen. Corker's concerns."
The setback came shortly after the nonpartisan Joint Committee on Taxation estimated that the plan would fall $1 trillion short of paying for itself, even after economic growth is taken into account. While GOP Senate leaders like John Cornyn of Texas and John Thune of South Dakota downplayed the findings, Corker pushed for a way to make up for the budget hole.
Republican Sens. Jeff Flake of Arizona and James Lankford of Oklahoma are among the other GOP senators with fears about the proposal ballooning budget deficits.
Sen. David Perdue of Georgia said his fellow Republicans are considering future tax increases not linked to any trigger as part of the bill.
Lawmakers are weighing whether to make corporate tax cuts in the plan expire in year six or seven, Reuters reported, citing a Republican senator and an aide.
Shortly before the parliamentarian's ruling, Corker, Flake and Sen. Ron Johnson of Wisconsin delayed voting on a measure to advance the bill as they talked with GOP leaders on the Senate floor. After the conversation, the senators voted to push ahead.
Republicans, who hold 52 seats, can only lose two votes and pass the bill if all Democrats and independents oppose it. They only need a simple majority, with a tiebreaking vote from Vice President Mike Pence, under special budget rules.
As the bill stands, it makes many individual tax cuts expire within a decade to comply with budget rules. The corporate tax rate reduction to 20 percent from 35 percent was expected to be permanent.
Reuters contributed to this report.