Saving for Retirement
In my view, Congress should amend the governing acts for retirement accounts to provide for a simple and penalty-free withdrawal from 401(k) and individual retirement accounts for the down payment on a first house, with the tax deferred on the income withdrawn (perhaps starting amortization at age 70½). We should give investing in a house of your own the same retirement-account tax treatment as investing in stocks and bonds.
Congress did have bills introduced in this direction in the 1990s—it would be a good bipartisan project to actually do it now.