Glad she's putting out feelers, but there is no legalistic test that defines whether or not an offense is an Impeachable offense.
As the Republicans found out, an action that may be "technically' illegal is NOT an Impeachable Offense unless the people view the action as an intolerable abuse of power.
On the other hand, if the public considers an action to be an intolerable abuse of power, that action is an Impeachable Offense, whether or not it is a violation of written law.
If the electorate demanded Impeachment for "negligent, stupid, mismanagement of a war", then Bush and Cheney could be charged with that “high crime” in the Articles of Impeachment.
It's all about political will. And political will is driven by citizen action. It is up to us.
Our representatives can look to the law for guidance, but they are not limited by the letter of the law. They can look to past Impeachments, but they are not bound by precedence. No "technical' interpretation of the law can trump the will of the people.
Demanding Impeachment is a short hand for all the stages. The first step is an Impeachment Inquiry. Clearly, we have sufficient evidence of wrong-doing to demand an Impeachment Inquiry.
Bush and Cheney have given us much to choose from. They have done things that are prohibited by law (malum prohibitum -- e.g., violating our laws against torture and laws against warrantless domestic spying). They have also committed offenses that are wrong on their face (malum in se -- e.g., "Lying a nation into war," "making boom threats" and "terrorizing the American people with threats of a mushroom cloud in 45 minutes.” .
There is no doubt that we have cause to move forward, even if all we look no farther than the information already in the public domain (e.g. the documents and analysis in
Hoodwinked provide the grounds for a dozen articles).