Interesting, which message do you want to reclaim? Right now there are a plethora of them. I don't think that there is a single person, currently running for Democratic President that does not have a different message from the other. In other words the left has NO single message but a confusing conglomeration of whatever. In other words, they are working, very hard, to demonstrate their inability to agree on a damned thing and there is, certainly, no specific message.
The talking heads of TV, for instance, are constantly bemoaning the fact that the Democrats have yet to define themselves, except the Biden. The rest just keep hoping that one of their messages gains steam.
I guess the real message goes something like; "whahoo!" (somethings gotta eventually stick?)