Nov 17 (Reuters) - U.S. President Donald Trump and Republican leaders in Congress want to pass tax-cut legislation by the end of this year. A measure passed the House of Representatives on Thursday, moving the action to the Senate, where the plan has already encountered resistance.
Republicans control the Senate by a 52-48 margin, leaving little room for defections. Here is a list of Republicans whose votes could be pivotal to the bill's fate.
Senator Ron Johnson of Wisconsin surprised colleagues on Wednesday by becoming the first Republican to announce opposition to the tax plan. That earned him a telephone call from Trump.
Johnson, formerly the chief executive of a polyester and plastics manufacturer, said he believed the legislation unfairly benefits corporations over small businesses. But he has said he hopes changes can be made that would enable him to support the bill in its final form.
Johnson said he believed Trump was sympathetic to his critique. He plans to meet with Treasury Secretary Steven Mnuchin, House Speaker Paul Ryan and other officials to work on fixes to the bill.
"I'm getting texts and emails from people all over the country ... that are saying: 'Stand firm, you are absolutely right,"' Johnson said.
Susan Collins, a moderate Maine Republican, has said she has qualms about the Senate leadership's plans to include repeal of the Obamacare individual mandate in the tax bill. The mandate requires people to buy health insurance or face a penalty.
Collins said her staff's research showed that for some middle-class Americans, higher insurance costs stemming from repeal of the individual mandate would outweigh the benefits of the tax cuts they would receive. Repealing the mandate to purchase health insurance could raise costs for consumers if fewer healthy people decide to obtain coverage.
Collins was among three Republicans who voted in July to block a Republican attempt to dismantle Obamacare, former Democratic President Barack Obama's signature healthcare law formally known as the Affordable Care Act.
Senator Bob Corker, a Trump critic who has decided not to run for re-election, has not taken a position on the tax bill. The Tennessee lawmaker said on Wednesday he had met with Mnuchin to discuss it.
As a deficit hawk, Corker's main concern is red ink - the tax bill is expected to add $1.5 trillion to the national debt over 10 years. "I'm still working with folks to see if there's some way to be assured that as it relates to the deficits issue, we're not going to create harm," said Corker, who chairs the Senate Foreign Relations Committee.
A phone call from Trump seems unlikely. Corker and Trump openly feuded last month, with Corker calling the White House an "adult day care center" after Trump attacked Corker repeatedly on Twitter.
Senator John McCain of Arizona, a former presidential nominee who has long prided himself on his reputation as a maverick, says he will wait for the final version of the tax-cut bill before announcing his position.
The former Navy pilot and chairman of the Senate Armed Services Committee infuriated Trump when he joined Collins and Senator Lisa Murkowski of Alaska in voting against the Senate bill last summer to repeal Obamacare.
McCain, who has kept working after a diagnosis of brain cancer, has said he has almost no working relationship with Trump and has criticized the administration on a wide range of matters.
Murkowski of Alaska chairs the Senate Energy and Natural Resources Committee and is a longtime proponent of opening up the Arctic National Wildlife Refuge, or ANWR, to oil and gas drilling.
That provides an enticement for her to support the tax bill. Her committee has passed legislation to open the refuge to oil drilling, and the measure is expected to be attached to the tax bill.
But Murkowski voted against three attempts to dismantle Obamacare in the summer, so the combination of the tax bill with a repeal of the Obamacare individual mandate may give her pause.
When asked on Wednesday whether she could support the combined tax bill and individual mandate repeal, she said only that she had been focused on ANWR.
Senator Jeff Flake of Arizona, a vocal Trump critic who is not seeking re-election in 2018, has issued a statement saying he appreciated the effort to fix the tax code but was worried about the impact on the national debt.
Senator James Lankford of Oklahoma, like Flake, is a conservative Republican. Lankford has been in private talks with Flake and others about opposing the tax plan on the grounds that it would balloon the national deficit, Time magazine reported on Thursday. A spokesman for Lankford, asked to comment on the report, said the senator was eager to work with colleagues to pass tax reform that simplifies the tax code, grows the economy, and ultimately pays down the debt.
Senator Rand Paul is a Kentucky Republican with a libertarian streak. Along with Trump, he called for combining the repeal of the individual mandate in Obamacare with the Republican tax-cut plan. But Paul has not said how he will vote on the tax bill.
(Reporting by Susan Cornwell in Washington; Editing by Caren Bohan and Peter Cooney)