Why Nancy Pelosi does not call for impeachment

I very rarely enter into direct political editorial. There are a few reasons for this, the most prevalent being that I prefer to use satire and mockery in my political editorials; and that the political dialogue in this country is so toxic that the moment you posit an opinion for one side or the other, you are immediately labeled as a "liberal," "conservative," "bleeding heart," "right wing nutjob," etc, despite the fact that most people cannot define these labels in any logical form.

(Hooray, for our ability for independent thought! Hooray!)

However, moments ago I read an article about a grassroots movement in the country calling for the impeachment of President Bush and Vice President Cheney. I have read many vitriolic articles about Speaker Pelosi's stance that, in her words, "impeachment is not on the table," words uttered moments after she became Speaker, articles claiming that she was caving in to the right wing in an effort for placate the mainstream media, and that she was no better than the present administration. I have read many other articles claiming that the idea for impeachment is just the Democratic grandstanding and an effort for divisiveness and to make political points with the more extreme elements of their base. Contentious on both sides, you can see.
Regardless of my personal view, whether or not Bush and Cheney should be impeached for deliberately using fraudulent intelligence to mislead the nation into the war in Iraq; or whether they should be applauded for attempting to rid the world of the worst terrorists in the world, and giving 500,000 people the opportunity to live in a society outside of religious and societal despotism and repression, I believe I have a new theory into why Nancy Pelosi has not called for impeachment, a theory that I have not seen debated or posited in any mainstream, or high-profile independent press. (Qualifier alert!: for those who need things blatantly spelled out for them: this does not mean that this theory has not been posited, just that I have not seen it posited.)
The Constitution lists the Order of Succession as follows (in my own words): If the President cannot serve, or is impeached, the Vice President would assume the role of the President. If the Vice President cannot serve as President, or is impeached or unable to assume these responsibilities, the second in line for succession is the Speaker of the House. This is the position that Nancy Pelosi has. Were she to call for the impeachment of President Bush and Vice President Cheney, scream show hosts, and other knee jerk reactionaries (read television pundits) would call her an opportunist, a self-serving hypocrite; would claim that she was abusing her power the moment she took control of being Speaker. Given the vitriol that would be sure to ensue, the reactions would undoubtedly be worse or just as bad as those screaming about the present administration and the war in Iraq, or the fervor over Alberto Gonzalez.

I believe that Nancy Pelosi's decision to not call for impeachment was a political calculation, and not based on how she really felt, if a politician can really have their own honest feelings on any subject. It was a decision based on political expediency and career enhancing motivations, certainly not for the benefit of the office.