The modern Left does not really want to win - because it is in essence oppositional and there is no specific state it can win to. Of course the Left wants, and has got, power; but what the Left does with power is precisely to ensure that there are no-winners; that there is a lose-lose scenario.
The greatest success of the Left is perhaps the Middle East in general, and the Israel-Palestine conflict in particular - no side is allowed to win or made able to win; both sides are alternately supported and demonised, all sides have lost badly over a long time; the situation of mutual immiseration is well established and sustained. The future envisaged is... more of the same.
Much the same is worked for in internal national affairs in The West. For fifty years in The West here has been growing a great polarisation and conflict between sexes, classes, races, natives and immigrants... no side has won, all sides have lost - there has been solidly establishes a mutual mistrust, resentment, simmering hatred.
And such a dire psychological situation is what the effort of Leftism is all about - because ultimately Leftism is anti-salvation; its goal is to induce people to reject Good and damn themelves by choice.
Unending conflict is no accident - this is precisely the Left's aim and purpose: no winners, a lose-lose scenario.