WASHINGTON (Reuters) - The White House said on Thursday a lot of progress was being made on tax reform after the “Big Six” Republican tax negotiators made up of administration officials and congressional leaders issued a statement on preparations for a tax reform bill. “We’re making a lot of progress on this front,” White House press secretary Sarah Sanders said at a news briefing. She singled out “simplification,” relief for the middle class and dropping the proposal for a border adjustment tax. 