Must you always respect other people?

In a comment on my previous post in civility, Dan Fincke linked to this older post of his, where he wrote:

Emotions can be employed in ways that are consistent with helping people reason better.  But resorting to name calling is bypassing reason and attacking people in a personal, disrespectful, uncivil way.  Religious people deserve no more respect than any one else.  I am not saying religious beliefs are at all off limits to the same aggressive queries and critical analysis that all other consequential (and even many inconsequential) beliefs should be.  Religion deserves no special deference and has no right to insist any one hold anything sacrosanct.  But religious people also deserve no less respect than anyone else.  It is the moral-political hallmark of Enlightened civilization that everyone is treated with respect regardless of their personal merits.  Respecting people does not mean having in every context to humor their bad ideas or soft-pedal one’s critical remarks about them.  Respect, in many cases, means believing that someone is strong enough and smart enough to handle honest, well-reasoned, well-intentioned criticism.  People who we pander to because we have contempt or fear for their supposed inabilities to handle what we really think are not people we respect but ones we patronize.

In a nutshell, true respect means giving people the truth, the whole truth, and nothing but the truth—but with no name calling.

But do we really always have to respect other people? You can argue that everyone deserves respect in some minimal sense. But given some of the truly awful specimens in the category “people,” it must be a very minimal sense. Even ignoring the mass murderers, there are still the people who send death threats over broken religious taboos (most of whom are too cowardly to ever carry them out), the people who poison public debates with lies, the ordinary bigots, and many others.