WASHINGTON - President Donald Trump on Thursday nominated former National Labor Relations Board member R. Alexander Acosta to serve as U.S. secretary of labor, one day after Trump's original choice withdrew.

Acosta is dean of the Florida International University College of Law in Miami and is Trump's first Hispanic nominee.

Acosta has had a decades-long public service career, serving in three presidentially appointed and Senate-confirmed positions, and is expected to face a smooth confirmation process.

"Mr. Acosta's nomination is off to a good start because he's already been confirmed by the Senate three times," said Sen. Lamar Alexander, who chairs the Senate Committee on Health, Education, Labor and Pensions that will be vetting the nomination.

Acosta was appointed to the National Labor Relations Board (NLRB) by former Republican President George W. Bush, who also appointed him to be assistant attorney general in the Justice Department's Civil Rights Division.

He was then appointed to be U.S. attorney for the Southern District of Florida, where he went after high-profile defendants such as Jack Abramoff and UBS, resulting in the Swiss bank paying more than $750 million in fines for a tax-avoidance scheme.

Acosta also previously served as a law clerk to Samuel Alito from 1994 to 1995, when the conservative Supreme Court justice was a judge at the 3rd U.S. Circuit Court of Appeals.

While at the NLRB, Acosta signed hundreds of opinions. Those familiar with his work describe him as a careful and cautious public servant whose career trajectory suggested he may someday vie for a federal judgeship.

Because he has already gone through multiple vettings by the Senate, it is unlikely there will be any surprises in his background that could derail his nomination.

The choice of Acosta, a traditional Republican conservative, is seen by some as a sign that Trump was forced to give up a more aggressive policy on worker issues.

Trump's first labor secretary pick, Andrew Puzder, the chief executive officer of CKE Restaurants Inc, was outspoken in opposition to issues such as overtime pay, minimum wage hikes and even discussed the superiority of robots over human workers.

He removed his name from consideration on Wednesday amid concerns he could not garner enough Senate votes to be confirmed.

"This is the humbling of Donald Trump," said Seth Harris, a former Acting Labor Secretary during the Obama administration, who said Puzder would have been a "radical disruptor" but Acosta won't be.

Acosta has been a staunch defender of the civil rights of Muslims who faced a backlash after the Sept. 11, 2001, attacks on the United States.

In a 2011 congressional hearing, Acosta applauded how the Justice Department responded to civil rights violations, saying they helped assure Muslim Americans that "their government would protect their rights."

But progressive groups were already responding negatively to the Acosta appointment with Allied Progress alleging he had mismanaged the Department of Justice's Civil Rights Division when he ran it. In 2008, an internal Justice Department report faulted Acosta for failing to rein in a staffer who engaged in improper politicized hiring.