President Donald Trump's choice of Senator Jeff Sessions as his attorney general was initially dogged by allegations of past racism.
The controversy has now moved on to meetings Mr Sessions had with the Russian ambassador during Mr Trump's election campaign.
Mr Sessions was one of Mr Trump's earliest supporters in his White House bid. As a key loyalist, he was a senior adviser to the New York tycoon on politics, national security and policy.
He was also a vice-chairman on the Trump presidential transition team.
'Lying under oath'
Mr Trump's campaign was dogged by allegations that some of his team had met with Russian officials and that Moscow had interfered in the election on his behalf.
Mr Sessions was revealed by the Washington Post to have met Ambassador Sergei Kislyak twice, despite telling his January confirmation hearing that he had had no contacts with the Russians during the campaign.
Democrats have accused him of "lying under oath" and say he must resign.
Russia: The scandal Trump can't shake
They have also called on him to step aside from an investigation by the FBI - which he oversees as attorney general - into the alleged Russian interference.
Mr Sessions met Mr Kislyak twice during the campaign / AP
Mr Sessions insists he "never met any Russian officials to discuss issues of the campaign". Mr Kislyak was one of 25 foreign ambassadors he met as a member of the Senate Armed Services Committee last year.
They held a private conversation in Mr Sessions's office in September and had spoken earlier in the summer, along with several other ambassadors, the Post said.
The KKK joke
The latest controversy follows that of alleged racist remarks by Mr Sessions in the past, which proved a roadblock in his political career and put him under fresh scrutiny for the attorney general post.
A Senate committee denied Mr Sessions a federal judgeship in 1989 after lawmakers heard testimony that he had used a racial slur.
Mr Sessions was an early supporter of Mr Trump / AP
He had also joked about the Ku Klux Klan, saying he thought they were OK until he heard they smoked marijuana.
The Alabama senator told the Senate Judiciary Committee at his confirmation testimony that allegations he had once supported the KKK were "damnably false".
Mr Sessions was also accused of calling a black assistant US attorney "boy" and telling him to be careful about how he spoke to "white folks".
He denied to the committee ever having called the lawyer "boy" and insisted he had merely advised him to be cautious about what he said to "folks".
Mr Sessions also rejected claims he had labelled the National Association for the Advancement of Colored People "un-American".
Democrats were outraged when Senator Elizabeth Warren, who opposed Mr Sessions' appointment as attorney general, was silenced by Republicans while trying to read a letter by Coretta Scott King that criticised him.
Writing in 1986, the civil rights activist alleged that he had "used the awesome powers of his office in a shabby attempt to intimidate and frighten elderly black voters".
Mr Sessions' supporters deny he is a racist, pointing to his votes to extend the Voting Rights Act and to award the Congressional Gold Medal to Rosa Parks.
Mr Sessions has spent much of his career fighting immigration battles, ranging from amnesty bills on creating a path to citizenship for undocumented immigrants to visa programmes for foreign workers.
Mr Sessions supports limiting legal immigration, arguing that it protects American jobs.
He also backs Mr Trump's plan to build a wall along the US-Mexican border.
In a 2005 Washington Post op-ed, he argued that, "legal immigration is the primary source of low-wage immigration into the United States".
The government, he argued, should be focused on "slowing the pace of new arrivals so that wages can rise, welfare rolls can shrink and the forces of assimilation can knit us all more closely together".
His strident views on immigration were laid out last year in his 25-page manifesto, "Immigration Handbook for the New Republican Majority". In the report, he argues immigration was responsible for job losses and welfare dependency.
He called claims by technology entrepreneurs that immigrant workers with elite skills were part of the innovation process a "hoax".
What's his background?
Born Jefferson Beauregard "Jeff" Sessions III, he became Alabama's attorney general before he joined the Senate in 1996.
He sat on the Senate Armed Services Committee, the Judiciary Committee and the Budget Committee.
The lawmaker, who helped Mr Trump craft his foreign policy plan, was one of the few Republicans to come to his defence after he proposed a temporary ban on Muslims entering the US.
Mr Sessions shown during his graduating year at Wilcox County High School / AP
When asked if he supported a temporary ban in his hearing, Mr Sessions said he did "not support the idea that Muslims as a religious group should be denied admission to the United States".
He has backed Mr Trump's amended proposal, now an executive order, banning individuals from countries with a history of terrorism, which is now being challenged in court.
Gay marriage opposition
Like many Republicans, Mr Sessions has opposed the LGBT-rights movement, and in particular the legalisation of same-sex marriage.
In 2000 and 2009 he voted against legislation which would expand the definition of a hate crime to include offences based on sexual orientation.
In 2015 after the Supreme Court voted to allow same-sex marriage across the US, he dubbed the decision an "effort to secularise, by force and intimidation".
But Mr Sessions testified in Tuesday's hearing he would follow the law of the land on gay rights.
As Alabama's attorney general in 1996, he fought vigorously to prevent an LGBT-rights conference from meeting at the University of Alabama.
He promised to prosecute school administrators under a state law passed in 1992 that made it illegal for public universities to fund a group that promotes "actions prohibited by the sodomy and sexual misconduct laws".
When the university pledged to allow the conference to meet, he sought a court order to prevent it, but ultimately the 1992 order was overturned by a federal judge.
What about Guantanamo?
Mr Sessions has challenged calls to close the prison at Guantanamo Bay, and he has also questioned whether terrorism suspects have the right to be tried in civilian courts.
During his confirmation hearing, Mr Sessions said he accepted the law "absolutely" prohibits waterboarding.
He also said Guantanamo Bay was a "safe place" that fits the purpose of keeping prisoners "marvellously well".
The National Rifle Association (NRA) applauded Mr Sessions' appointment as America's top prosecutor, saying he would "make America a safer place by prosecuting violent criminals while protecting the Second Amendment rights of law-abiding gun owners".
Mr Sessions is rated A+ by the group, indicating that he has a pro-gun voting record.
He has previously voted against background checks at gun shows, and in favour of banning lawsuits against gun manufacturers, and allowing firearms in checked baggage on trains.
In a statement at his confirmation hearing he promised a crackdown on gun violence, saying: "If I am confirmed, we will systematically prosecute criminals who use guns in committing crimes."
Many in the law enforcement community have voiced support for Mr Sessions, believing he will be a strong advocate for the police.