The Senate Finance Committee approved its tax reform bill, sending it to a full Senate where some Republicans are skeptical.
The panel voted along party lines late Thursday to advance the Republican proposal.
Committee Chairman Sen. Orrin Hatch, R-Utah, called the bill's advancement a "historic moment."
"Bringing our outdated tax structure into the 21st century will help level the playing field for businesses — both small and large — and ensure we can keep more jobs and more investment here at home," Hatch said in a statement.
The White House released a statement applauding the committee for advancing the bill.
Reiterating its call for passing the tax bill by the end of the year, the White House said, "This legislation cuts taxes for middle-income families and empowers American businesses to create more jobs, increase wages, and propel our economy toward a brighter future."
GOP Senate leaders hope the full Senate can pass the bill after the chamber takes a week off for Thanksgiving. But Republicans will face challenges in passing the bill when they return.
One GOP senator — Ron Johnson of Wisconsin — this week said he would oppose the bill as written. Multiple other GOP senators have also expressed doubts about the plan, creating uncertainty that it can pass only with the narrow Republican majority.
The GOP, which holds 52 seats in the Senate, can only see two defections and still pass the bill with a simple majority under special budget rules.
The bill would permanently chop the corporate tax rate to 20 percent from 35 percent, while making temporary changes to individual income tax rates and several deductions. It would also effectively repeal the Obamacare provision requiring most Americans to buy health insurance or pay a penalty.
Making individual tax cuts temporary and scrapping Obamacare's individual mandate help Republicans to raise revenue and comply with budget rules. But those moves raise the political stakes for supporting the bill.
Sen. Susan Collins, R-Maine, has already expressed concerns about the estimated health-care premium increases caused by the individual mandate repeal.