Bruce Bartlett tells all in his blog:

“Josh Bolten and I often worked together during the George H.W. Bush administration… a couple of years into the current administration, I saw him at a reception. I had just started writing some mildly critical things about some of Mr. Bush’s policies. … I was taken aback when I went up to Mr. Bolten to say hello and he pointedly turned his back on me and walked away. I guess he thought he was punishing me for my criticism.” (HT: Brad DeLong)