Focusing on the "white working class" is too broad. They need to target more narrow segments if they want to make gains.
* Continue to support unions (and not just union leadership)
* Economically support the working class who have genuine economic need at the bottom - minimum wage, health care, tax credits, etc.
* Support small business over large corporations
* Support small farmers over corporate farmers
* Work harder to improve education quality in low-income neighborhoods, including rural
* Support the indebted poor over creditors
* Support home ownership among the poor and renters' rights over landlords
Even if they can't win the ethereal "white working class", there are gains to be made still in all those segments. And if they can position themselves as essential to people's livelihoods in those areas then they'll lose less ground when it comes to culture wars.
This strategy has worked before. Remember that the Democrats held the House for 40 straight years until 1994. They were still winning presidential elections in West Virginia, Kentucky, Tennessee, Missouri, Arkansas, and Louisiana in 1996, Indiana and North Carolina in 2008, Iowa, Ohio, Florida, and Maine in 2012. They had a Kentucky senator until 1998, South Dakota and South Carolina until 2004, Nebraska until 2012, Montana, South Dakota, Iowa, Arkansas, Louisiana, West Virginia, and North Carolina until 2014, Missouri, Florida, Indiana, and North Dakota until 2018, and Alabama until 2020. They were still considered the pro-black, pro-immigrant, pro-abortion, pro-gay, anti-gun party back then, they only won because at least some white people in certain states still put economic shyt first. It can happen again but Democrats need to deliver more than they have.