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 may be removed from office and never allowed to hold a government position again if he is found guilty. Our 17th president, Andrew Johnson, was impeached while in office. Thirty-five senators found him guilty -- just one vote short of the two-thirds vote necessary to convict him. President Richard Nixon resigned from office rather than face impeachment charges in the Watergate scandal in 1974. President Bill Clinton became the second president to be impeached by the House in 1998. Later, the Senate found him not guilty.