@engineer,
Maybe the passion is not there because many feel they already know who is going to win the primary. People just don't get excited by Hillary even if they support her and vote for her. Perhaps Hillary and her team is digging up everything they can on Trump and they will run a negative campaign against Trump. I know we like to think ourselves above all that, but some feeling has got to come from somewhere and if she don't, she is liable to be drowned out by Trump trying to discuss issues.
(sorry meant this reply to snood)