While at his new job with the Red Cross, may he find redemption for the following:

• Implementing a program to privatize tax debt collection
• Privatizing regulations
• Offering early retirement to estate tax auditors
• Potentially politicizing tax collection (see OMB Watch's Advocacy Blog for more instances of potential politicization)
• Forcing TRAC to sue IRS to get tax data that shows how many corporate audits are cursory and unproductive

Oh, and for not really doing much to close the tax gap, though Congress never gave him a big enough budget to do anything significant.