No, failed the working class. Since the eighties the Democratic party has been on a heavy neoliberal kick. One which result resulted in massive damage to unions Nationwide. Don't forget that it was Bill Clinton who signed an HW Bush initiative in NAFTA. Don't forget the Barack Obama allied with Republicans to push free trade agreements. Don't forget that Kamala Harris walked back a lot of the pro Union rhetoric that Joe Biden campaigned on.
Sometime in the '70s Democrats started losing control of the working class and the unions. Richard Nixon spearheaded that movement and was successful in it. Much like we're seeing today he couched it in counterculture. It's a part of our history that we don't talk about enough. Nor do Democrats pay enough attention to class in general.
Would you mind explaining the how the presence of the Gadsden flag on its own shows that "the Democratic Party has failed the working class"? I just don't exactly understand your comparison.