Political pundits like to accuse opponents of a “politics of fear”, or of hate. In contrast, folks go out of their way to emphasize that theirs is a politics of hope or compassion. Yet when each of us notices that we are feeling fear or hate, this doesn’t usually make us reject the beliefs that lead to such feelings. Why do we embrace and accept our own fears and hates, even as we suggest that others’ fears and hates are bad signs about them?
One obvious explanation: relative to low status folks, high status folks have less occassion to fear or hate. Pretty pampered prestigious people encounter fewer dangers to fear, or powerful enemies to hate. Therefore publicly showing fear or hate is a sign of low status. Complaining that your opponents have a “politics of fear” or hate is really just complaining about their low status. Politics isn’t about policy, after all.
Perhaps out of a genuine fear of the politics of hate and fear? (a bit contradictory I know - "the only thing we have to fear is fear itself") Hate and fear has been used to deprive people of their civil rights and sometimes has lead whole societies into disaster by military misadventure. Hatred and fear of Jews, of kulaks, of capitalists, of Catholics, of Protestants, of "reactionaries" has led to vast numbers of deaths.
Furthermore, that other people are aware of the sometimes disastrous consequences of the politics of hate and fear makes it rhetorically useful to draw implicit comparisons. If I agree with you that, say, the French Revolution's collapse into the Great Terror and then into a military dictatorship was a bad thing, and was driven in part by politics of hate and fear, saying that x is the politics of hate and fear probably increases the odds that I'll start to regard x as a bad thing (unless we're fundamentally opposed).
Re: "Why do we embrace and accept our own fears and hates, even as we suggest that others’ fears and hates are bad signs about them?"
Fear signalling is often an attempt at manipulation - as in the "crying wolf" story. If someone tells to to be afraid, be very afraid, then you should often look to see what they will get out of this.