I think that's a bit of an exaggeration. You're right though when they lose the Democrats tend to run right. That's how we got Clinton. However by winning Democrats tend to Trend left. Continued winning is how we got the strongest string of civil rights and labor rights victories in American history. So not necessarily overwhelming destructive Victory but consistent Victory I think would move us further left. There's of course the other way which is the Grassroots Ray which is what Republicans have done. First with the tea party then with the trump movement. Consistent victories at small levels lend results to National levels. Their party moved much further the right because they moved it from the ground up. Both are options and both can be done simultaneously.