If you thought the White House was done devising bad economic policies, think again. First was the idea to pass a stimulus package that many economists agreed was too large and worsened inflation; then came the plan to shrink the domestic oil and gas industry; next, a push to remake and enlarge the welfare state that never had popular support and, mercifully, faltered in Congress; and now, tucked away in President Biden’s budget proposal, comes a provision for a de facto wealth tax. In some ways, this is the worst idea of them all, though it would be so hard to enforce that its damage would be limited, even if it passed.