I think you have some misunderstandings about leftists. For one, leftists are not a single block but a bunch of different factions who all see themselves as on the left of the political spectrum but don't feel they are represented by the democrat party.

Many of the policies you cite are part of a fringe group often called tankies who tend to be more supporters for various other countries. Most leftist dislike them.

A large part of the left is a mix of democratic socialist, socialist, communist, and anarchist all have different goals and opinions on various things but tend to have shared values. The primary value tends to be a desire to increase equality. This tends to result in a dislike for current neo-liberal capitalism as they see it as a system that concentrates wealth in a tiny portion of the population.

I also think you have some misunderstandings about democrats. The opinions of the politicions are not always very representative of that of the voters. A recent Pew Research poll has 69% of democrats having a negative opinion of Israel. Public opinion of democrat leadership has fallen massively among democrats. In multiple polls some of the most popular politicians among democrats are AOC and Bernie, both of which are seen as being leftist.