In an NYT Op-Ed, Ramesh Ponnuru observes that none of the current presidential candidates are discussing expanding the current Child Tax credit, a move that would help middle income American families:

What would be a serious middle-class tax cut? One answer is to expand the tax credit for children. But none of the candidates is proposing to do so, or any other big tax relief for regular folks.

Why indeed, are candidates from both parties not pushing this?