If there were any question about their sanity you'd need look no further than to Nancy Pelosi who they have placed at the top of the heap in their Cult of Personality.
Yech!
IMO, the leadership of the Democrat party along with most Democrat politicians, are nothing more than political opportunist. Liberalism is far more subject to being co-opted by opportunist than conservatism. That is why the Dems appear to be fascists. They really do not care about the common man or the common good - only to the extent that these serve them as political advantage.
They fancy socialism not because they think it will help people, but because socialism will help the opportunist politician gain and maintain power. When their opportunism is taken further it looks like fascism. When taken to extremes, it looks like communism (more exactly, Stalin-ism).
The thing that today's Dems lack is the guts to be communists. Lacking guts seems to afflict the Repubs, too, but its manifestation is to have the leadership of the Repubs look like...er...well...Trent Lott.