How Consequential Was the Fed Tightening in 2008?

So Senator Ted Cruz's claim that Fed policy was too tight in 2008 and my ringing endorsement of it has generated some interesting conversations. Paul Krugman says I should taper my enthusiasm, while Scott Sumner and Ramesh Ponnuru say it is okay. The Washington Examiner and Quartz seem to agree.

Other observers like Kevin Drum, Jeff Spross, Cullen Roche, and Sudeep Reddy are underwhelmed by Senator Cruz's critique. They acknowledge the Fed should have cut interest rates at its August and September 2008 FOMC meetings, but they question how consequential this inaction was to the Great Recession. After all, the Fed could only cut interest rates from 2% to 0% during this time.