What is "pandering" and what is legitimate engagement with a particular group's concerns?

Barack Obama's 2002 anti-Iraq War speech was described, in another thread, as "pandering". The sincerity of his presence at that rally was also questioned because Senator Obama stated that he didn't oppose all war(a position shared by Eugene McCarthy and Dennis Kucinich, among many other well-known and honorable Democrats and progressives.

My questions are:

A) Why should Obama's speech at this rally be considered pandering, rather than a valid expression of principle? And why would anyone imply that this speech gave Obama an unfair advantage in the Senate race over some inherently superior Democratic opponent?

B) What is the moment you decided that a particular candidate, any candidate, is pandering rather than genuinely engaging the issues a particular group, any group, is raising? Is there anyone here who would actually argue that antiwar activists, or progressive activists in general, have no right to expect to have a say in the choice of the Democratic ticket, or in American politics at any level? Is there anyone who would consider themselves "left-of-center", "liberal" or "progressive" who thinks that only big donors and elected officials should decide what our party stands for?

C) If the next Democratic president did exclude antiwar activists or progressives from having any meaningful say in the party or in policy, could that Democratic president possibly do anything that was actually different than what a Republican president would do?

A) ... rather than a valid expression of principle

If he had voted the way Kucinich had in not to fund it, maybe that would be valid.

intentional boosting of bad policy for political advantage. Pandering.