Julian Zelizer is a professor of history and public affairs at Princeton University. He is the author of "Jimmy Carter" and "Governing America."

(CNN) -- Something good can come of the bad news about taxes. Last week there were more revelations about who knew what, and what actually occurred, when the Internal Revenue Service targeted conservative organizations that were seeking tax-exempt status. Former IRS Commissioner Doug Shulman told Congress he was "dismayed" about what had happened.

Taxes were front and center once again when Apple CEO Tim Cook was forced to respond to a congressional report that the company had avoided paying billions of dollars in taxes.

The controversies generated a big stir in Washington and the news media, though it is unclear that the general public is quite as interested as the politicians and the reporters. Nonetheless, at least for now, both stories have produced intense congressional investigations to find out who was responsible for any wrongdoing.

While investigations to determine whether laws were violated and who should be blamed are important, it is also crucial that Congress use these moments as opportunities to reform processes and laws that are broken....