"As for the charge that George W. Bush's grandfather was a Nazi collaborator of some sort, put forward in Phillip's book "American Dynasty," Peter Schweizer demonstrates why this is such a bad-faith slander:

One of Phillip's most attention-grabbing chapters posits the theory that the Bushes were involved in the rise of Adolf Hitler. While he correctly notes that Brown Brothers Harriman, an investment-banking firm employing Prescott Bush and George H. Walker (George W. Bush's great-grandfather), investing in Nazi-era German companies, Phillips fails to note that it was Averell Harriman, later FDR's ambassador to Moscow and Truman's commerce secretary, who initiated these investments (and some in Soviet Russia) before either of the Bushes joined the firm. Prescott Bush did not oversee these investments: the reality is that he was involved almost exclusively in managing the firm's domestic portfolio. It was Harriman who largely managed the foreign investments and, accordingly, it was he who met German and Soviet leaders. (Peter Schweizer, "Kevin Phillip's Politics of Deceit," National Review Online, March 30, 2004,
www.nationalreview.com/comment/schweizer200403300907.asp 
[accessed Jan. 23, 2007])'