The New Republic has a list of successful progressive reforms that conservatives opposed. It focuses on quotes from conservatives that today look bad. My guess is that one could comb through the back issues of their magazine and find quotes that are equally embarrassing.
Just in case you were convinced by the list that progressives are always right, here are a few progressive visions that did not work out so well:
--Roosevelt's National Recovery Administration cartels
--New Deal policies to restrict farm output (which persist to this day)
--"fine tuning" the economy in the 1960's and 1970's
--wage-price guideposts and controls in the 60's and 70's
--Carter-era energy policy
--government aid programs for developing countries
--welfare programs of the 1960's
--just about anything done in the name of "affordable housing"
If I were looking for embarrassing quotes from the left, I could start with "I have seen the future and it works." I could go on to quote Galbraith on the essential similarity between the planning done in the U.S. and Soviet economies (the only difference being that in the U.S. some of the technocrats work inside large corporations) and on the alleged importance of the entrepreneur being nothing but a myth. I could Krugman on the greatness of Enron (when he was on its Board) and on the overwhelming economy-wide significance of Enron's failure (when it collapsed).
Anyway, coming up with a list of the most embarrassing statements of one's opponents is a really vapid exercise. The last thing we need to do is reinforce confirmation bias.
Instead, list your own most embarrassing statements. I challenge commenters to list their own. Here are mine:
1. I took note of high house prices during what we now know was a bubble, but I thought it would take a much larger rise in interest rates to cause a big drop. Along the same lines, I said that none of the highly-regulated firms would be hurt in the sub-prime crisis. At least I said that in the early drafts of FP2P, and that was one of the few things I deleted during the late stages of editing the book.
2. I bet Bryan that the Republicans would not win a branch of government between now and 2017. While I might not lose that bet, I certainly have no desire to double down.
3. I know I had another argument with Bryan this year where I had to concede to him, but right now I cannot remember the topic. Selective memory strikes again.
4. I discount somewhat the embarrassment of my bizarre theories of money and exchange in ancient times, because I always preface those theories by saying that they are wrong.
5. I wrongly accused Brad DeLong of changing his mind about Greenspan's conduct of monetary policy after the crisis. Brad may be in the process of changing his mind now, but in an intellectually honest way.
6. There are many more, which I cannot think of right at the moment. But don't remind me. Let me keep my selective memory.