"There's increasing space for a new coalition from the center left to the center right," Bill Galston, senior fellow at Washington D.C.-based Brookings Institution, said in a phone interview. "If you imagine that the Republican Party ticket in 2020 is headed by Donald Trump and Democratic ticket is headed by Bernie Sanders, I would predict that there would be a well-financed third party ticket. That would be the greatest opportunity in two generations to change the basic structure of American party politics."
"If I were keeping score, I would rate this as fulfilling a campaign promise," said Bill Galston, a former Clinton administration official now at the Brookings Institution. "Any move is significant and the world is right to regard it as a serious step."