Republicans hold a 52-48 majority in the Senate, meaning they can only lose two dissenters, with Vice President Mike Pence poised to vote for the changes in the event of a 50-50 tie. He has sought a "backstop" that would create automatic tax increases if the tax bill doesn't spur strong economic growth as Republicans have promised.
The legislation faces an open amendment process on the Senate floor that may spell substantial changes before a final vote that's expected Thursday.
In a boost for the measure, the Senate Budget Committee advanced the bill to the full Senate on a 12-11 vote.
A number of senators however, including Republicans Ron Johnson of Wisconsin and Bob Corker of Tennessee, still have problems with the legislation. Sen. The House would keep individuals' state and local property tax deduction, which the Senate bill would eliminate.
Trump said as he meets with Republican House Speaker Paul Ryan and Republican Senate Majority Leader Mitch McConnell that Schumer and Pelosi are weak on crime and combating illegal immigration and want to increase taxes.
Wall Street moved higher on the news that the bill would move to a full Senate vote, with the benchmark S&P 500 .SPX index closing up a little over 1 percent.
Johnson has complained that the package doesn't cut taxes enough for business owners who report business profits on their individual tax returns.
One of the main differences between Republicans and Democrats is that Republicans, in general, favor less government and more tax cuts. "It's just a justification to let those who have argued that they don't believe in increasing the deficit actually vote for a bill which does exactly that", Merkley said.
Given the debacle over the failure to repeal Obamacare earlier this year, tax reform has become a must-win for the GOP and is the last chance for Trump to claim a legacy building achievement at the moment - in his debut year in office - when the President's power is traditionally at its apex. "We've got four-and-a-half hours", Corker told CNN's Manu Raju ahead of the crunch Budget Committee meeting.
"What we're hearing from the White House is not what's in the bill", said Sen. John Thune (R-S.D.), the No. 3 Senate GOP leader, said Monday evening, predicting success.
Democrats who oppose the GOP tax bill have repeatedly cast it as a plan helping corporations and the wealthy at the expense of poorer Americans.
A change to the state and local tax deduction: One of the thorniest issues during the House debate on the TCJA concerned the state and local tax deduction, which allows households to deduct state taxes from their federal tax bill. Republicans in the two chambers would have to come to an agreement on a consensus bill.
Ten months into his presidency, Trump is looking for passage of his first significant piece of legislation. Corker, speaking on CNBC, said he liked much of the bill's business provisions but had a dim view of the rest of it.