However from a practical standpoint, for the Speaker to succeed, both the President and the Vice President would have to die at the same time. The idea that Bush and Cheney could be impeached simultaneously is absurd and everyone knows it. Not to mention that there is no scenario that gives the 'Rats 67 votes in the Senate to remove either of them.
Yes... and no.
Section 2 of the 25th Ammendment states: "Whenever there is a vacancy in the office of the Vice President, the President shall nominate a Vice President who shall take office upon confirmation by a majority vote of both Houses of Congress."
A more likely scenario than the one you proposed would be the President passing away, and while the new Vice President is awaiting confirmation, the new President (formerly VP) also passes. e.g, Assassination and a heart attack the following month.
God willing, we never see that scenario play out regardless of who's in office.
I've said it before and I'll say it again: I have absolutely no doubt that if the Dems take control of either house, an extreme lefty will try to assassinate the president and veep. They are unhinged little creatures.
They could be impeached sequentially; all the Senate need do is refuse to confirm a new Vice-President until after Cheney is impeached.
Not to mention that there is no scenario that gives the 'Rats 67 votes in the Senate to remove either of them.
And then Hillary Clinton opened up her private collection of FBI files...