Donald Trump closed in on a major political victory Thursday in the US Senate, where his controversial tax reform bill received a boost from the influential John McCain, even though he is often at odds with the president.
The Republican majority appeared likely to adopt the bill – in what would be the first-year president’s most significant legislative achievement to date – though a few defections remained possible.
The vote, late Thursday or possibly Friday, was expected to be tight.
The legislative psychodrama was shaping up in a way that mirrored the Republican effort this summer to dismantle the Obamacare health law: in a dramatic late-night vote, three Republican senators, including McCain, torpedoed the repeal that Trump had repeatedly promised during his election campaign.
This time, however, the Republican majority appears more solidly united – McCain himself said Thursday he was on board – around the underlying philosophy of tax reform: a significant corporate tax rate reduction and smaller cuts for most individuals, along with a simplification meant to allow Americans to file their taxes ‘on a postcard.’ 
These changes, Republicans insist, will bring relief to a financially strained middle class while sharply boosting economic growth.
‘I believe this legislation, though far from perfect, would enhance American competitiveness, boost the economy, and provide long overdue tax relief for middle-class families,’ McCain said in a statement.
Lingering doubts
But some doubt remained Thursday whether all 52 Republican senators in the 100-member chamber would ultimately support the plan.
Some conservatives bridle at seeing their party trample the anti-deficit budget orthodoxy they preached during the Obama presidency: the bill before them would balloon the national deficit by $1.4 trillion over the coming decade, the Congressional Budget Office estimates.
Other senators have raised narrower concerns: over the tax rates for certain smaller companies; deductions for families with children; or a provision, slipped into the legislation, to end the requirement that all taxpayers carry health insurance or pay a fine – a central pillar of Obamacare.
And the corporate tax rate might end up being 21 or 22 percent, rather than the 20 percent Trump has called for, in order to pay for some of the tweaks. The current rate is 35 percent.
‘The Republicans have the Senate. The Republicans have the House. The Republicans have the White House. It’s very unusual,’ Trump said Wednesday in the Midwestern state of Missouri. 
‘This is our chance to free our economy and our workers from the terrible tax burden in Washington.’
Biggest tax-law change in years
If the legislation passes the Senate, it still must be reconciled with a House version passed on November 16. The tax plans differ on some points.
As Republican leaders scrambled to overcome final objections and lock down necessary votes, their essential argument was a simple one: If they fail to pass tax reform, they can expect major losses in next November’s midterm elections.
Republican Senator Lindsey Graham summed up the challenge this way: ’52 people are trying to buy a car…. We may not all agree on the color or the type car, but if we don’t get a car, we’re all going to walk. And most people don’t want to walk. They’d rather have a car.’
In Graham’s folksy terms, senators were voting on a series of amendments over the color and make of their future ride.
Democrats see boost for rich
Democrats, united in opposition, are arguing that the plan is too expensive and will accommodate only the rich.
Senator Mazie Hirono used some salty language to get the point across.
‘Rather than crafting a tax plan that would actually help middle-class families, Donald Trump and the Republican Party have decided to screw them over instead,’ the normally reserved Hawaiian said on the Senate floor.
Analyses suggest most people at all income levels will get immediate help from the tax cuts, but that the wealthiest five percent of households – including many Republican donors – will profit disproportionately.
Trump, his administration and Republican lawmakers argue that the plan will jolt the US economy into high gear, leading to what Senator Pat Roberts called ‘an American renaissance.’ 
The Joint Committee on Taxation projected Thursday that US gross domestic product would receive a 0.8 percent bump from the plan, translating to $458 billion in increased revenues over 10 years.
But that would only partially offset the conventional projection of $1.414 trillion in lost revenue over the same period due to the tax overhaul.
Will Senate Republicans stand together when the time comes to vote, and then negotiate a compromise strong enough to pass both chambers in the weeks ahead? 
The administration believes so.
‘We think that we’re going to get it done by the end of the year,’ White House spokeswoman Sarah Sanders told reporters.