Politics in America is a contact sport. Passions flare and the rhetoric can get heated and nasty. Political parties stoke these fires, playing on people’s fears as a key fund-raising tactic.

Conservative authors have produced books with insulting titles like “If Democrats Had Any Brains, They Would Be Republicans” and “Liberalism is a Mental Disorder.” The political left counters with ugly titles like “The I Hate Ann Coulter, Bill O’Reilly, Rush Limbaugh … Reader,” “The I Hate Dick Cheney … Reader,” and “The I Hate George W. Bush Reader.”

It is ironic, yet natural, that the political left dominates hate literature. The irony is that the left championed “hate crimes” legislation. Having outlawed public expressions of hatred against various groups—racial, linguistic, sexual orientation, etc.—the left sees nothing hypocritical about fomenting hatred toward people of a different political orientation. Even if the “hate” authors don’t personally hate Bush et al., people on the left must realize how such ugly language can poison susceptible minds.

While ironic, it is not surprising that hatred of political opponents is so virulent on the left. Hatred has long been a central pillar of leftist ideologies, premised as they are on trampling individual rights for the sake of a collectivist plan. Karl Marx boasted that he was “the greatest hater of the so-called positive.”

In 1923, V.I. Lenin chillingly declared to the Soviet Commissars of Education, “We must teach our children to hate. Hatred is the basis of communism.” In his tract “Left-Wing Communism,” Lenin went so far as to assert that hatred was “the basis of every socialist and Communist movement.”

Indeed, it is easy to see the thread of hatred running through the various illiberal regimes of history, whether Soviet or Chinese communism or Hitler’s national socialism. Only hatred could explain the willingness to kill, enslave, and rob vast numbers of innocent human beings. Hatred corrodes one’s conscience.

Under its toxic influence, a person will regard man’s God-given right to be secure in his life, liberty, and property as nuisances to be overcome, not commandments to be obeyed. The flip side of hatred is an inflated self-love, self-importance, and self-righteousness so extreme that respect for other human beings diminishes and, in extreme cases (Stalin, Mao, Castro, Kim, et al.), disappears.

An incident recounted in the late Alexander Solzhenitsyn’s The Gulag Archipelago illustrates this mental deformity. Soviet officials wanted to transport heavier loads of steel by railroad. When railroad engineers said that heavier loads would break down the tracks, they were shot as saboteurs of progress.

When the loads were then increased, the tracks indeed broke down. Political goals could not nullify the principles of engineering.

A leftist conceit is that will-power can change the way the world works. It can’t. This mad tendency persists today; signs of it are all around. A recent letter to the editor angrily insisted that the law of supply and demand didn’t cause high gasoline prices, but that (what else?) evil oil companies did.

The writer then vilified Americans for using too much gasoline (thereby contradicting his earlier statement that demand was irrelevant). So full of hatred is this writer that he spews contempt for economic laws.

In his arrogant egotism, he blames the world’s problems on the fact that millions of people make choices that he—who fancies himself more enlightened and morally superior to his fellows—thinks they shouldn’t make. Welcome to the soul of leftism/illiberalism.

Hatred of individuals for ideological reasons is pathetic to behold. After conservative journalist Tony Snow passed on from a horrible disease, posters on the leftwing blog Daily Kos wrote “rest in hell” and “[I hope] there really is a hell and [Snow]’s burning in it now.” How tragically self-demeaning such hatred is. It is a great sickness of spirit.

Former Alaska Gov. Sarah Palin was the object of vicious vituperation and seething hatred (like the threat by comedienne Sandra Bernhard that Palin would be gang-raped if she campaigned in New York City). Perhaps her female attackers feel rebuked by her decision to choose life for babies. Perhaps they feel inadequate by comparison. When I see their contorted faces and hear the desperate unhappiness in their voices, I feel sorry for them and pray that the venom might leave their hearts.

Hatred, of course, knows no ideological bounds. Let us all refuse to forward such nastiness. Indulging hatred is playing with fire. On an individual level, it ruins one’s happiness and disposition. On a societal level, it exacerbates the venomous miasma that pollutes our political discourse.

Let us debate ideas and policies, but never condemn individuals. In Christian terms, let us strive to hate the sin and, if not love the sinner, at least refuse to hate him.

Dr. Mark W. Hendrickson is an adjunct faculty member, economist, and fellow for economic and social policy with The Center for Vision & Values at Grove City College.