have been shock and disbelief. i would have thought she is an out hraoeur and not anything more than a fringe movement maybe. but that s not the case any more. reporter: barbara studied civil conflict for years, from yugoslavia to northern ireland. experts who study wars and study the warning signs have been talking about them. but nobody wanted to believe it. and january 6th made it impossible to deny and ignore that there really was this cancer growing in our own country. there was a threat that was mobilizing. reporter: she warns right wing media, social media, and from trump himself has put the united states on a perilous path.
and american elections? no. i mean, i think whoever wins, wins. i m all about that. he will win if he runs again. but the people that know that we were cheated are almost at the point of saying i don t want to vote because it ll happen again. reporter: what is your reaction to hearing from an american like that? well, ten years ago it would have been shock. and disbelief. and i would have thought, well, she is an outlier and she s not representative of anything larger than fringe movement maybe but of course that is not the case anymore. reporter: barbara walter is a professor at the university of california in san diego. she has studied civil conflict for years from yugoslavia to northern ireland. experts who study civil wars and know the warning signs, we ve been talking about them but nobody wanted to believe it. and january 6th made it impossible to deny and ignore that there really was this cancer growing in our own country.
point of saying i don t want to vote because it ll happen again. reporter: what is your reaction to hearing from an american like that? well, ten years ago it would have been shock. and disbelief. and i would have thought, well, she is an outlier and she s not representative of anything larger than fringe movement maybe but of course that is not the case anymore. reporter: barbara walter is a professor at the university of california in san diego. she has studied civil conflict for years from yugoslavia to northern ireland. experts who study civil wars and know the warning signs, we ve been talking about them but nobody wanted to believe it. and january 6th made it impossible to deny and ignore that there really was this cancer growing in our own country. there was a threat that was mobilizing.
reporter: barbara walter is a professor at the university of california in san diego. she has studied civil conflict for years from yugoslavia to northern ireland. experts who study civil wars and know the warning signs, we ve been talking about them, but nobody wanted to believe it. and january 6th made it impossible to deny and ignore that there really was this cancer growing in our own country. stop the steal! there was a threat that was mobilizing. reporter: she warns the constant barrage of lies undermining elections from right wing media, on social media, and from trump himself has put the united states on a perilous path. citizens do believe what they are hearing, and if they hear it long enough and consistently enough and if that s all they hear, they absolutely don t think it s a lie. they think it s the truth. will you trust the next