John Harding removes himself from consideration to head it . `` Ultimately , my goal was to improve the security of our nation 's transportation systems . He admitted ` ` making mistakes '' in prior dealings as a contractor . Harding was Obama 's second nominee to head the agency .
John Harding removes himself from consideration to head it . He admitted ` ` making mistakes '' in prior dealings as a contractor . Harding was Obama 's second nominee to head the agency .