Nepotism is defined as the practice among those with power or influence of favoring relatives or friends, especially by giving them jobs. The term originated with the assignment of nephews to important positions by Catholic popes and bishops. The word comes from the Italian word nepotismo, which is based on the Latin word nepos meaning nephew.
After becoming president, Trump appointed his son-in-law, Jared Kushner, and his daughter, Ivanka, who is married to Kushner, into advisory roles to the president in 2017. Neither receives a salary, because “advisor” is not an official tax-paid government employee position. Nevertheless, they receive secret service protection and are able to use government vehicles and aircraft. Those are expenses that do cost tax payers money. They also have used their positions to promote or facilitate family business, something which President Trump frequently does. He frequently meets supporters, donors, and others seeking favors at properties he owns.
There is a federal law that “generally prohibits a federal official, including a Member of Congress, from appointing, promoting, or recommending for appointment or promotion any ‘relative’ of the official to any agency or department over which the official exercises authority or control.” As can be seen from this, Trump is able to get around this law by appointing his daughter and son-in-law as “advisors” and not to actual government posts.
Trump is not the first president to use nepotism. President Ulysses S. Grant, who was the 18th president from 1869 to 1877 enabled about 30 of his family members to prosper financially in some way from either government appointments or employment. John F. Kennedy made his brother Robert F. Kennedy the Attorney General and his brother-in-law, Sargent Shriver, the first director of the Peace Corps. When Bill Clinton became president he appointed his wife Hillary to chair a Task Force on National Health Care Reform.
Nepotism is not restricted just to politicians, but is also often found in businesses. It is not uncommon to see management positions filled by family members. As long as such members provide adequate services this practice is not condemned, but if appointment of incompetent family members results in a decline in business or other adverse results, especially if more qualified individuals have been passed over, then the practice is condemned.
 縁故主義  https://ethics.house.gov/staff-rights-and-duties/nepotism#:~:text=Federal%20law%2C%20at%205%20U.S.C.,official%20exercises%20authority%20or%20control.