The past week demonstrates how Campaign 2012 has devolved into a series of calculated personal attacks, devoid of the substantive issues and policies that should be dominating the national political conversation.

The main exhibit: Mitt Romney spent most of the week dodging questions about his tax returns and defending his record at Bain Capital, specifically addressing a report that he was actually at the financial firm three years after he supposedly left. Romney still insists that he will not release more tax returns and, on Sunday, his campaign declared that its man had “retroactively retired” from Bain (whatever that means).

In his latest New York Times column, Paul Krugman defends the Obama campaign from charges that it is focusing more on Romney’s personal history than issues of substance. Krugman’s main point: Not only do these issues matter but, contrary to popular belief, they actually help bring policy issues out to the forefront.

— Posted by Tracy Bloom