German Foreign Minister Sigmar Gabriel did not mince words on Saturday.

Ivanka Trump's visit to Germany last week "was treated almost like a world event," he said, "while the mix of politics with family and business reminds us instead of nepotism and would be unimaginable here."

That's not quite true, but laws significantly restrict nepotism in Germany. Christian Lammert, a political science professor at the Free University of Berlin's John F. Kennedy Institute, said that in general cases of nepotism are investigated more thoroughly in Europe - and that they have political consequences.

'A royal family'

After US President Donald Trump's daughter participated in the G20 women's empowerment summit in Berlin last month at the invitation of German Chancellor Angela Merkel, Foreign Minister Gabriel said he felt consternation that members of a family "who have never been elected show up suddenly as official state representatives and are treated almost as if they were members of a royal family."

Ivanka Trump at the high-level Berlin conference

The criticism did not just come from Gabriel. Trump, a 35-year-old former model and private businesswoman, represented the US government at the Berlin summit without any legitimization - "and that is in fact highly problematic," Lammert told DW.

Lammert said Trump had filled his White House with relatives in a way that could lead to corruption. "Family members are set up in key positions without confirmation - positions that allow them to take influence while at the same time, they have implications for their private businesses," Lammert said. He pointed out, for examples, that President Trump's tax plan would be a massive benefit to him and his family and that Ivanka and her husband, Jared Kushner, sit in on meetings with foreign politicians whose countries they do business with.

Lack of transparency

In a recent interview with Britain's Telegraph, the president's middle son, Eric, praised nepotism as "a beautiful thing."

Trump calls herself "an unpaid employee in the White House office, subject to all of the same rules as other federal employees." Critics argue that her position as a senior presidential adviser violates a 1967 federal anti-nepotism statute, even if she does not draw a salary. The statute states that no public official - and that includes the president - may hire or promote a relative.

Ivanka and her husband have assumed powerful roles in Trump's White House

Good governance requires making processes transparent, and that is not the case at all in the Trump administration, Lammert said, adding that the president has not grasped what it means to be a legitimate leader. "He doesn't know the difference between an enterprise and a democratically ruled country," Lammert said, "and he can't differentiate between public goods and private interests."

Under a Trump presidency, "what were once isolated incidents could become a way of governing," Henry Carey, an associate political science professor at Georgia State University, warned on the website The Conversation in January.

"When the closest advisers, both institutional (in the case of son-in-law Jared Kushner) and informal (in the case of his three children), are dominated by family members, the decision-making process will not only be influenced by private family interests but also tend to ignore legal procedures."