Referred to this topic in an earlier post, but this possibly could indicate why democratic socialism, at least by its immediate connotations, may not become a viable alternative in the U.S. for a long time, from Jason Schulman and Joseph Schwartz:

Hopes for a rapid democratic transition to socialism were shattered by the horrors of Stalinism and the failure of social democratic governments to discern a socialist road out of the Great Depression. After World War II, ‘democratic socialism’ increasingly became identified with the ‘Keynesian’ welfare state… with the crisis of the welfare state due to the end of post-WWII growth in the 1970s, the mainstream left … faced a crisis of vision and program.”

One could say that they’ve yet to get it back.