Leftist parties should talk a bit more about the same stuff that the right-wingers do. Would rather have a left-wing party bait people into voting for them with immigration rhetoric, instead of the fash.

What is then going to happen is that leftist values-voters will abandon those parties, so the parties deflate and still can't govern. And if the new voters who were "baited" stay for a second electoral cycle, they then take control of the party and turn it into what we didn't want to exist in the first place.

You win voters by convincing them that you have the best answers to their problems and the expertise to implement them.