If they whack the Republicans over the separation of church and state.
If they whack the Republicans over Nixon dropping the gold standard and causing all that inflation worldwide. Honest money helps the poor and middle class more than those who have accountants and lawyers!
If they come up with a reasonable reparations plan for the slavery issue that is amenable to at least 50% of both African Americans and the rest of the population (it wasn't nothing!). Let's have a referendum. We can make it a combination of tax cuts and a tax credit so it would help both the poor and the middle class. It could be spread out over a number of years.
If they can finally see that lower taxes help the poor more than redistribution. The Democrats should propose a program that gets rid of the income tax for foster children, victims of child abuse, anything traumatic like that. At least for five years anyway.
The Democrats should propose that we lower the income tax rate by 1% a year until revenues from the tax go down for more than two years and then raise it until revenues go down so that we can find the optimum rate for growth and revenue. We should do this separately for the capital gains tax. Once we find the optimum rates, we should stick to them! And we should have a flat tax, with the first so many dollars exempt.
There is no reason for the right to own these economic issues. The debate over socialism is over and the debate should now be whether the government is going to tample your individual rights or not. Most people who vote Republican would switch in a minute if offered an alternative that embraced economic AND individual freedom.