Extremism occurs among the political left and the political right. But to listen to some media, you would think that the violent-prone are all conservatives.

Regardless of how extreme the new $2.4-trillion healthcare law may be, it’s wrong to threaten or commit acts of violence because of it.

Even as polls show that most Americans disfavor the new law, the media have focused selectively on the most radical opponents — those few who have threatened or committed violence — as if they were typical.

I know how seriously death threats must be taken. My home was under special police watch during part of my 14 years as a congressman. Eventually, a man went to prison for threatening to kill and dismember me.

Real threats should not be confused with harassment, however. Combining them into a single number — overstating them for political purposes — is a dishonest effort to sway public opinion. The same is true when unbalanced attention is given to threats against Democrats with little regard to threats against Republicans.

After the healthcare vote, Democratic lawmakers Bart Stupak of Michigan, Louise Slaughter of New York, and Tom Perriello of Virginia reported threats against their lives. Rep. Betsy Markey, D-Colo., asked for police to watch her home.

GOP leaders such as House Republican Leader John Boehner of Ohio immediately condemned these threats, as did tea party groups.

As Politico reported, “There hasn't been any hard evidence that the reported harassment is linked to the tea party movement, but Democrats have tried to draw the link between the harassment and the sometimes-inflammatory rhetoric that tea partiers and Republicans deployed in opposing the health care overhaul.”

Lack of evidence did not stop high-ranking supporters of the healthcare bill from using the situation to depict opponents as dangerous wingnuts.

Rep. Chris Van Hollen, D-Md., accused protesters of "stoking the flames" of violence. Rep. James Clyburn, D-S.C., accused Republicans of “aiding and abetting . . . terrorism." Others made similar remarks. President Obama used the claims to mount a fund-raising appeal.

But where was their outrage about threats to kill Sen. Jim Bunning, R-Ky., only two weeks before? Bunning was menaced because he filibustered against $13 billion in deficit spending to expand unemployment benefits.

And how about House Republican Whip Eric Cantor, R-Va., who opposed the healthcare bill? When a bullet was fired into his office window, he reported it to the police — not the media — to avoid inciting violence.

Political violence is wrong. Selective condemnation of that violence is also wrong. It should not be used to malign political foes for partisan purposes.

Overheated rhetoric also knows no political bounds. In an MSNBC discussion of civility and threats in politics, progressive host Ed Schultz didn’t like it when I mentioned his February statement about former Vice President Dick Cheney’s heart: “We ought to rip it out and kick it around and stuff it back in him.”

Schultz now defends his words as a metaphor about heart transplants and who receives healthcare. But if the political left feels free to use such figures of speech, why do they condemn the language of the right?

Because I represented Oklahoma City in Congress, I know that Timothy McVeigh’s deadly bombing of our federal building was not the act of a mainstream political activist. Those on the left tend to overlook another mass murderer, the Unabomber Ted Kaczynski, who killed people by sending 16 package bombs to advance his extreme environmentalist throwback agenda. They also ignore the violent trashing of Seattle by socialist-leaning anarchists.

Back in Oklahoma, State Rep. Sally Kerns, a Republican, reported multiple death threats from homosexual activists because she criticized their lifestyle. In California, many who supported Proposition 8 in California (banning same-sex marriage) reported similar threats. Meantime, supporters of the gay agenda mourned the murder of a gay leader, San Francisco Supervisor Harvey Milk, by a fellow Democrat.

In my case, my life was threatened by an extremist because I opposed the legalization of marijuana. He was apprehended, tried, and sent to prison.

Violence against political leaders is neither new nor unique to America, and the motives are diverse. One survey reports that nine American presidents have been attacked (four killed), as have three candidates, plus seven U.S. senators, nine congressmen, eight governors, 11 mayors, and 17 state legislators. I always remember that I saw President John F. Kennedy a few hours before a Communist sympathizer shot him in 1963.

The point is simple: Extremism and violence historically exist on both ends of the political spectrum. Nobody should seek to advance their politics — as we are witnessing right now — by pretending that all menacing fanatics are at the other end of the political spectrum. Nor should the occasional use of common political metaphors (“hit list,” ”targeting” politicians for defeat, etc.) be mistaken as threatening.

We hear differing views on President Obama’s new healthcare law.

RealClearPolitics.com averages the various public opinion polls, now showing about 50 percent in opposition and 40 percent in support. Any political pro can tell you that a 10 percent margin in election terms is a landslide.

Obviously, a lot of Americans are angry. But anger need not lead to violence. Those who mock groups like tea party protesters are often trying to provoke them — a provocation that must be resisted.

Like millions of Americans, I see the new healthcare law as a danger to civil liberties, an overreach of federal constitutional authority, a job-killing mandate and a step toward bankrupting the country.

The American way to change this is our system of quiet revolutions through elections. The controversy over this law should be resolved in the political process. Overheated rhetoric is protected as free speech. But it’s over the line and wrong to suggest that either major party favors the use of violence instead.

Ernest Istook is a Distinguished Fellow at The Heritage Foundation. He was a congressman for 14 years.