By Aruna Viswanatha and Julia Edwards
WASHINGTON, Jan 28 (Reuters) - U.S. President Barack Obama's pick for his next attorney general faces a Senate confirmation hearing on Wednesday that will likely highlight tensions between the Obama administration and the new Republican Congress.
Loretta Lynch, nominated to the post in November, has stirred little controversy in her 16 years with the U.S. Attorney's office in Brooklyn and is expected to win confirmation.
But she is likely to face hours of grilling from the Senate Judiciary Committee on hot button issues including immigration, guns, civil rights, national security, and her relationship with congressional Republicans, who frequently clashed with Attorney General Eric Holder, an unapologetic liberal voice and one of Obama's closest allies.
Some Republicans have threatened to use the nomination process as a battleground to defy Obama's November immigration order, which eased the threat of deportation for some 5 million undocumented immigrants.
One Republican, David Vitter, has already said he will vote "no" and complained that Lynch did not answer his questions on immigration and other topics when they met earlier this month. Chuck Grassley, who chairs the committee, has said he plans to keep the hearing going until lawmakers ask all their questions.
"There are obviously ongoing disputes between the administration and particular senators, and the nominee becomes the vehicle by which those disputes are aired," said Ronald Weich, a former top Justice Department official on legislative affairs who is now dean at the University of Baltimore's law school.
Lynch, 55, would be the first black woman to lead the department, coming to the post amid tensions between black communities and law enforcement after grand juries failed to indict two white police officers who killed unarmed black men in separate incidents in Ferguson, Missouri and New York City.
She has built a reputation as a diligent prosecutor who avoids the spotlight, bringing big cases against terrorists and global banks, and dealing with more mundane issues on an Attorney General's advisory committee like phone trees and the use of toner at U.S. Attorney's offices.
She is also known for her diplomatic style, which has earned her praise from unexpected corners.
"She's an impressive prosecutor, a U.S. attorney and professional," Senator John Cornyn, the second-ranking Republican in the Senate, told reporters on Tuesday. "For me, anything that would expedite Eric Holder's retirement is a good thing." (Reporting by Aruna Viswanatha and Julia Edwards in Washington, additional reporting by Emily Stephenson and Richard Cowan; Editing by Alan Crosby)