You will hear people say that due to pollination, air pollution, or the intervention of the Alien Overlords (OK. I made that last one up. But people get a little extremist at times) there is no such thing as organic food any more.
Yes, any government official can be impeached - Presidents, Legislators & Judges, etc. But you can't impeach people for doing a bad job. Impeachment is necessarily dependent upon a charge of criminal or significant unethical behavior to warrant removal. Yes, Granholm is awful, but we're stuck with her for 4 more years.
The President of the Senate may also preside over most of the impeachment trials of federal officers. However, whenever the President of the United States is impeached, the US Constitution requires the Chief Justice of the United States to preside over the Senate for the trial. The Constitution is silent as to the presiding officer in the instance where the vice president is the officer impeached.