In a single word:
NO!
I am not aware of any decisions that would allow a sitting President or Vice President to be indicted by a Grand Jury. If anyone else knows of any relevant cases, please comment below.
But, since this question has been going around given the recent revelation from George Stephanopoulos:
"...President Bush and Vice President Cheney were actually involved in some of these discussions."
... and given the WaPo's recent article indicating Fitz is thinking of bringing conspiracy charges ... and given all the recent hub-bub around Senator Obama's recent diary, I thought it'd be a good idea to discuss what we want the Democrats in congress to do, should Fitz eventually name President Bush or Vice President Cheney as unindicted co-conspirators ( aka doing the Nixon dance ) ...
I'll keep this short and sweet:
IF
President Bush or Vice President Cheney are eventually named as unindicted co-conspirators or material witnesses in l'affaire Plame
AND
congressional democrats fail to stand up in unison and DEMAND their resignations ...
THEN
I WILL NO LONGER VOTE FOR THEM AGAIN. EVER. PERIOD.
This. Will. Most. Definately. Be. A. Litmus. Test. Issue. For. Me.
Thank you.
Update [2005-10-2 12:35:4 by manyoso]:
This is important because we have a precedent thanks to Nixon for unindicted co-conspiring sitting Presidents. And that is they RESIGN. Presumably to face charges... Sure, they cut a deal with their successors for backhanded pardons, but at least Bush would be out of office. That is why the first words out of every congressional Democrat, like a mantra all over the air waves, when and if Fitz names Bush/Cheney as unindicted co-conspirators should be, "Nixon precedent" and calls for resignation.