As the U.S. president deals with the impeachment inquiry, Joe Biden's son Hunter has unwillingly become a key figure. He had been on the board of Ukranian energy company Burisma, which Donald Trump thinks a former prosecutor was investigating for corruption before he was removed at the behest of former U.S. vice president Joe Biden.

That theory has been discredited, but Trump had already urged foreign leaders to look into Joe Biden, who is also the leading Democratic front-runner.

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Timeline of key events in Trump-Biden-Ukraine controversy

Hunter Biden isn't a stranger to the limelight. He grew up in a prominent political family, but took a path different from that of his father and deceased brother Beau. While those two devoted their lives to public office, Biden leveraged his family's political connections to go up the business ladder.

The years soon after his graduation initially suggested that like begets like. All three graduated from law school, and Biden returned to Wilmington in the state of Delaware shortly after Yale Law to help with his father's run for the county council. But during that time, he worked as a lawyer at a banking holding company known as MBNA America, which, according to a New Yorker interview with Biden, was one of the largest donors to his father's campaign.

Biden continued to tap into this networking goldmine after he left what he considered a stifling corporate environment. He got in touch with William Daley, former president Bill Clinton's commerce secretary who had worked on his father's campaign. Daley told the New Yorker that he related to Biden's experience of growing up in a political family, and soon got him a job in the department as a policy director on the internet economy. Biden's career is littered with such instances.

Hunter Biden was very attached to his older brother Joseph, widely known as Beau, through a childhood marred by tragedy. During a Christmas shopping trip, a tractor-trailer rammed into his family's car, killing their mother and younger sister in the front while injuring the two boys in the back. His father had wanted to give up the Senate seat that he had just won to care for the grieving family, but pressed on after leading politicians convinced him to do so.

Like Beau, Biden answered his country's call to military service, becoming a reserve member in the navy at the late age of 42. Whereas his brother was deployed to Iraq as a captain in the Delaware National Guard, Hunter Biden was discharged in 2014 after testing positive for cocaine.

Trump's Ukraine controversy also isn't Biden's first encounter with widespread press coverage. His relationships have long been fodder for tabloid gossip. Biden's first marriage had been strained by his addictions, primarily to alcohol. In their divorce papers filed in 2017, Biden's ex-wife claimed that he had spent "extravagantly" on drugs, prostitutes, and gifts for women with whom he had sexual relations.

After Beau's death from brain cancer in 2015 at the age of 46, Biden noted that he spent a lot of time with his brother's wife Hallie, sharing a "specific grief" for Beau. They became a couple, with the public support of his father, but broke up after moving in together. He cited external pressure for the split and his subsequent move to Los Angeles. He is now married to Melissa Cohen, a South African filmmaker and fellow divorcee. 

Although it's not uncommon for relatives of politicians to benefit from proximity to power – Trump's daughter and her husband come to mind – we forget that even the most experienced public servants struggle with conflicts of interest. Joe Biden has said he avoids talking about Hunter's business dealings, but now that his presidential campaign is on the line, transparency with each other and with the public would go a long way.

(Cover graphic by Gao Hongmei)