Ximena Ortiz draws a distinction:
"While Obama’s positions on important foreign-policy issues have not always been static (even to some degree on the Iraq War), Obama has demonstrated a willingness to acknowledge his prior position. Obama has therefore not resorted to that dark art of politics, alchemizing one’s prior positions in order to avoid acknowledging misjudgments or contradictions... the main dichotomy between Obama’s and Hillary Clinton’s Iraq positions may be that while Clinton has obfuscated to some degree on her 2002 vote, Obama has not equivocated on what position he took in 2002, even though he may at times have doubted whether or not he had made the correct call on the war."
The difference between a dissembler and a doubter, between pure politics and intellectual honesty.