We have the NY Times piece showing that Rove helped pick US Attorneys and judges. We have video of a hearing where Democrats prove that Karl Rove's Deputy, Scott Jennings, was giving political briefings to government employees (a huge no no). Taken individually, these two scandals show the White House's, and Rove's, disdain for the rule of law.
Taken together, they show how Karl Rove uses his position in the White House to politicize everything - the judiciary, prosecutions, government employees. To Rove, everything is an opportunity to use any method to give the GOP an advantage. He has no policy goals, no ethics, all he craves is power. It is the ultimate justice that his methods, and this Presidency, gave power back to the Democrats.