WASHINGTON, Oct 9 (Reuters) - A public feud between President Donald Trump and Senate Republican maverick Bob Corker could narrow the path for enacting tax reform in the U.S. Senate, where a Republican go-it-alone effort is already showing signs of disunity.
Days after the Republican-controlled Congress took two important steps toward advancing tax legislation, a Trump-Corker shouting match threatened to further alienate Trump from key Republican senators such as John McCain, who prevented the party earlier this year from repealing Obamacare.
The political stakes could not be higher for Republicans. Tax reform offers them a chance to show they can govern and woo voters for the November 2018 midterm elections.
Trump and top Republicans have unveiled a plan to slash taxes for businesses and individuals, the first comprehensive overhaul of the U.S. tax code since 1986. They hope to complete the monumental task by January.
But the tax reform push has been dogged by delays and distractions such as Trump's criticisms of his own party's leaders including Senate Republican leader Mitch McConnell and House of Representatives Speaker Paul Ryan.
"Trump is running an outside game working to appeal to his core base of support and doesn't necessarily care how this may or may not affect his relationship with the Senate," said Ron Bonjean, a Republican strategist with close ties to Congress and the White House.
The latest incident erupted on Sunday. Trump lashed out at Corker in a series of derisive tweets saying the lawmaker had begged the president for his endorsement and announced his retirement after being turned down.
Corker replied in his own tweet describing the White House as an adult day care center, and then told the New York Times that Trump risks setting the nation on the path to "World War Three".
The spat is exactly what Republicans do not need as they move tax legislation through the Senate, which they control by only a 52-48 margin. Most Democrats are united in opposition to the plan, and Republicans cannot pass it if they lose support from more than two lawmakers of their own party.
"This is a delicate balance," said Stephen Moore, a fellow for the conservative Heritage Foundation who helped write Trump's campaign tax plan. "It all comes down to whether you can get 50 votes in the Senate. Right now, by my count, theyre at about 48. A few votes short."
Divisions have already emerged over proposals to repeal the federal inheritance tax and a popular deduction for state and local taxes. Another maverick, Senate Republican Rand Paul, has expressed unhappiness over reports that Trump's tax plan could raise taxes on some middle class Americans.
Republicans cannot afford to have Corker become a maverick like McCain. A key player in the tax debate, Corker helped the Senate move closer to legislation by agreeing to a budget resolution that would allow tax reform to lose $1.5 trillion in revenue over a decade.
But he has vowed not to vote for any tax package that adds to the federal deficit. Republicans hope Corker will ultimately vote for tax reform in hopes of boosting economic growth, but analysts say Trump's derisive tweets do not help, especially now that the Tennessee Republican has announced his retirement.
"Bob Corker, at this point, is as free as John McCain is to do what he thinks is right," said William Galston, former domestic policy adviser to President Bill Clinton.
Republicans dismissed Trump's fight with Corker.
"While it may really bother other Senate Republicans and it's unnerving that one of their own is being attacked, most arent retiring and know they must still work with the White House or answer to frustrated voters," Bonjean said. (Reporting by David Morgan; Editing by Kevin Drawbaugh and David Gregorio)