I believe that the standard that must be used for judging behavior in a campaign is whether or not you would consider the same behavior to be appropriate and justified if done against those you support by those you oppose. I believe that bad behavior is never justified because the other guy did it also or by the justness of your cause or the evilness of your opponent. For years conservatives have accused liberals of moral relativism on issues such as abortion, yet preached in support of the same types of moral relativism in other arenas. The fact is that extremists believe that they support the one truth and that actions in support of that truth or in opposition to those who believe differently are always justified no matter how despicable -- thus, extremism is defense of liberty is no vice. Not considered, of course, are conflicting notions of what constitutes liberty.
Personally, I believe that your morality is defined by how you act, not by the ideological or religious beliefs that you might use to defend your actions. If it is wrong to steal emails, for example, it is wrong whether the emails are stolen from university researchers in an effort to discredit a global environmental conference or it involves stealing emails from Republican members of congress to look for embarrassing references based on color, religion or gender. Both should be investigated and prosecuted with equal vigor. If it is wrong to hire investigators to examine every aspect of Palin's life, it is equally wrong to do the same to Obama. Do you actually believe that Obama opponents spent less money and resources investigating Obama than Palin opponents spent investigating Palin? Look just at the millions spent on the Birther issue with no credible evidence whatsoever.
Personally, I welcome the widespread investigations of public figures in politics. However, I do believe that there should be no relaxation of libel laws in those cases. If you recklessly and maliciously repeat a lie about a political candidate during an election campaign, you should be liable for full civil and criminal penalties. In fact, maybe we should expand those penalties to include exclusion from holding public office and from broadcasting on television, radio, or any other media that is public in its nature. But then, how would Fox fill the other 23 hours of the day?