Have Biden and the Democrats already hit their high water mark?

That might get $1 trillion or so over a decade. To get a lot more, there are meritorious but politically powerful targets: treating capital gains, which primarily benefit the affluent, as ordinary income; a big increase in the estate tax, where almost all the benefits accrue to heirs of the rich; or energy or other business-related taxes. An easy one should be to give the Internal Revenue Service a bigger budget for more efficient technology and audits. Former IRS commissioner John Koskinen has told me several times that every extra dollar spent on enforcement brings in another $5 to $10 in collections.

But few Republicans buy any of this. Neither do enough Democrats — so tax increases won’t come anywhere near what’s required to pay for most of the priorities.

The president’s campaign proposals would cost $1.7 trillion to $2 trillion for climate change, another $2 trillion in infrastructure (some overlap), another $1 trillion to extend the one-year increase in the child tax credit and earned income tax credit just enacted, and probably another trillion for bolstering health care, child care, and free community college tuition/college debt reform.

The few drops of any added revenues won’t begin to fill the much larger bucket required for these spending measures.