WASHINGTON — It wasn’t difficult for Barack Obama and Eric Holder to be in the same orbit. Both were sons of immigrants, Columbia Ivy Leaguers, basketball fans and prominent African-American political figures.

They first met nearly 10 years ago, dinner guests of a mutual Washington friend who seated Holder next to the newly elected senator from Illinois.

On Thursday, Obama announced Holder would be stepping down as his attorney general, one of his longest serving Cabinet members.

“This is bittersweet,” the president said.

Holder, who will stay on the job until his successor is confirmed by the Senate, was at his side.

“In good times and in bad, in things personal and in things professional, you have been there for me,” he told Obama.

Indeed, over the course of six years on the job, Holder has had his ups and downs. He also has become a rare figure: a close Washington friend of the president.

As attorney general, Holder aggressively enforced the Voting Rights Act, addressed drug-sentencing guidelines that led to disparities between white and black convicts, extended legal benefits to same-sex couples and refused to defend a law that allowed states to disregard gay marriages. He oversaw the decision to prosecute terror suspects in U.S. civilian courts instead of at Guantanamo Bay, Cuba, and helped establish a legal rationale for lethal drone strikes on suspects overseas. All were Obama priorities.