What exactly doest this verb mean (besides 'to cook sth quickly')?
It can also mean to prepare and execute a plan, or as Ray says, to stir up.
So, whip up can be used to describe an action when somebody tries to create some particular attitude of, for example, public towards some issue(s) or to heighten someone's emotions/attitude/ideas/thoughts about sth, if they already exist. Is it right?
P.S. This usage resembles (for me at least) a coachman who whips a horse to make it run faster, doesn't it?