Stephen F. Cohen, professor emeritus of Russian studies at New York University and Princeton, spoke Thursday evening with Fox News' Tucker Carlson about the latest shoes to drop in the investigations into the Trump campaign's possible ties to Russia. The Wall Street Journal reported late Thursday that Michael Flynn, President Trump's former national security advisor, has told the FBI and congressional investigators that he is willing to be interviewed in exchange for a grant of immunity from prosecution -- not a particularly good sign for the Trump White House. Cohen, one of the country's foremost experts on Russia, has been...