The request comes as Democrats are working to paint Republicans as corrupt and highlight their plans to investigate Trump should they win the midterm elections.
Some lawmakers and commentators have turned their attention to the possibility that Republicans in Congress could try to block Democrats from assuming the majority.
Senator Darline Graham, appointed to fill the Senate seat of her late brother, Lindsey, gently disagreed with the president’s decision to exempt Russia from the sanctions legislation.
Federal law enforcement officials said they were investigating a series of letters mailed to members of Congress and secretaries of state in recent days.
A New York Times analysis of Senator Susan Collins’s voting record shows that she frequently breaks with Republicans but more seldom changes an outcome.