Trump critics have charged that Kushner's White House role runs afoul of a 1967 law that forbids executive branch agency heads from appointing family members to positions in the department they oversee. It also prohibits anyone hired in contravention of the statute from being paid by the U.S. Treasury.
The opinion paves the way for Kushner, 35, to join Trump in the West Wing.
As for what his duties will include at the White House, President Trump has already said that Jared Kushner, an orthodox Jew, will be involved in the Middle East peace process and be the President' personal representative to Israel.
Sidman said another marcher spoke to Kushner, asking if he was indeed Jared Kushner's brother.
Q+A: The crisis in The Gambia
A regional military force awaited orders to roll into the capital and force Yahya Jammeh from the office he held for 22 years. He declared a state of emergency earlier this week, while the parliament has extended his term in office by three months.
Joshua Kushner has not previously been openly unsupportive of his brother's role in the Trump Administration.
Ivanka Trump and her husband Jared Kushner dance at the Liberty Ball at the Washington DC Convention Center following Donald Trump's inauguration as the 45th President of the United States, in Washington, DC, on January 20, 2017. "He has been incredibly successful, in both business and now politics". "Any appointment to that staff, however, carries with it a set of legal restrictions, by which Congress has regulated and fenced in the conduct of federal officials".
He also wrote that it was unlikely that Congress could bar a president from obtaining informal, ad hoc policy advice from a relative, and a major effect of allowing Kushner's appointment to a formal role is that he will be subject to the usual ethics rules for White House employees, such as conflict-of-interest laws.
Following his appointment, Kushner said he was "energized by the shared passion of the (president) and the American people.".