Thomas Heffelfinger was on the to be fired list before he resigned
Robert's Stochastic Thoughts 25/4/07
Marisa Taylor and Margaret Talev of McKlatchy on 26/4/07
Congressional investigators probing the firings of eight U.S. attorneys saw Thomas Heffelfinger's name on a version of the list
via Josh Marshall (of course)
I learned it from Fired Up Missouri which didn't make the claim explicitly while reporting "Documents released by the U.S. Department of Justice indicate that former U.S. Attorney Todd Graves was forced out of his post by the Bush Administration." Graves was replaced by voting fraud fraudster and civil wrongs division administrator Bradley Schlozman