Bill Clinton was impeached primarily for criminal conduct: lying under oath and misleading a federal grand jury about his affair with Monica Lewinsky. Nixon would have been impeached for a wide array of criminal acts, as well as abuses of power.
People don't realize that the Obama Administration has been, if anything, harder on whistleblowers than the Bush Administration. Part of the reason is that they know that the response will be more muted because the traditional constituency supporting whistleblowers just happen to be the same constituency as Obama's.
Obama is as likely to be impeached as he is to be installed as the next pontiff. And I say that as someone who has testified in Congress that this president has violated federal laws, unconstitutionally appointed various executive-branch officers and improperly transferred money.
Our carefully constructed system of checks and balances is being negated by the rise of a fourth branch, an administrative state of sprawling departments and agencies that govern with increasing autonomy and decreasing transparency.
Under the common law, one of the more controversial rules is the 'no duty to rescue rule' that says that, if you were not responsible for placing someone in danger or risk, you have no obligation to help them, even when it would cost little to save their life.