From the article Seneca linked:
When the Bush administration was discovered to have erased millions of emails illegally sent by 22 administration officials through private, RNC-owned accounts, in order to thwart an investigation into the politically motivated firing of eight US attorneys, just one talk show covered it that Sunday.
When Mitt Romney wiped servers, sold government hard drives to his closest aides and spent $100,000 in taxpayer money to destroy his administration’s emails, it was barely an issue.
When Hillary Clinton asked Colin Powell how he managed to use a Blackberry while serving as Secretary of State, he replied by detailing his method of intentionally bypassing federal record-keeping laws:
I didn’t have a Blackberry. What I did do was have a personal computer that was hooked up to a private phone line (sounds ancient.) So I could communicate with a wide range of friends directly without it going through the State Department servers. I even used it to do business with some foreign leaders and some of the senior folks in the Department on their personal email accounts. I did the same thing on the road in hotels.
... There is a real danger. If it is public that you have a BlackBerry and it it [sic] government and you are using it, government or not, to do business, it may become an official record and subject to the law.
Yet the fact that Hillary Clinton emailed through a private server and didn’t use it to cover anything up is somehow the defining issue of her campaign. “My God,” people cry, “anyone else would be in jail!”