After a summer of frustrating coverage, conservative movement leaders are taking aim at the Southern Poverty Law Center's most important source of influence -- the news media.

On Wednesday, a coalition of leaders from powerful conservative organizations sent a letter to news outlets, pleading with them to avoid citing the SPLC in their reporting. "All reputable news organizations should immediately stop using the SPLC's descriptions of individuals and organizations based on its obvious political prejudices," the letter says.

In recent months, and especially in the wake of the violence in Charlottesville, Va., major media outlets have cited the liberal nonprofit in their reporting on active hate groups, unfairly maligning conservative organizations that SPLC has lumped in with neo-Nazis and the Ku Klux Klan. This practice has drawn criticism from observers on both the Left and Right for years, a point the letter makes sure to emphasize in its appeal to journalists.

"The SPLC is an attack dog of the political left," leaders argue. "Having evolved from laudable origins battling the Klan in the 1970's, the SPLC has realized the profitability of defamation, churning out fundraising letters, and publishing ‘hit pieces' on conservatives to promote its agenda and pad its substantial endowment (of $319 million)."

"Anyone who opposes them, including many Protestants, Catholics, Jews, Muslims, and traditional conservatives," the letter continues, "is slandered and slapped with the ‘extremist' label or even worse, their ‘hate group' designation. At one point, the SPLC even added Dr. Ben Carson to its ‘extremist' list because of his biblical views (and only took him off the list after public outcry)."

Signatories made sure to clarify they do not believe the press intentionally cites the SPLC to target proponents of traditional values, but cited the case of Floyd Lee Corkins, who shot a security officer at the headquarters of the Family Research Council five years ago based on the SPLC's "Hate Map," to underscore the dangers of naming similar groups to that list.

"We believe the media outlets that have cited the SPLC in recent days have not intended to target mainstream political groups for violent attack," explains the letter, "but by recklessly linking the Charlottesville melee to the mainstream groups named on the SPLC website – those that advocate in the courts, the halls of Congress, and the press for the protection of conventional, Judeo-Christian values – we are left to wonder if another Floyd Lee Corkins will soon be incited to violence by this incendiary information."

The Family Research Council, whose president Tony Perkins signed the document, galvanized other conservative movement figureheads to support their cause, including Brent Bozell of the Media Research Center, former Attorney General Ed Meese, now at the Heritage Foundation, Tea Party Patriots President Jenny Beth Martin, and more than forty other representatives from leading groups who added their signatures to the letter in solidarity.

"To associate public interest law firms and think tanks with neo-Nazis and the KKK is unconscionable," they write, "and it represents the height of irresponsible journalism to do so."

The letter asks whether journalists would run a story based on a hypothetical "Here's Where the Baby Killers are Located in Your State" map produced by a pro-life advocacy group to illustrate its argument, correctly asserting the press would never publish such an article.

The SPLC's fraudulent categorizations are prominent largely because the media continues to rely on them when attempting to report on the proliferation hate groups. By making their case to the press, these conservatives are wisely appealing to the SPLC's most powerful source of influence.

It's objectively wrong for the SPLC to associate groups such as FRC and Alliance Defending Freedom with white supremacist organizations under its broad label of hate, but if they believe traditional family values are as noxious as neo-Nazism, they are within their rights to say so. It's the media's duty, however, to assess the objectivity of their sources. The time for outlets to stop relying on the SPLC as such a source is long past due. The organization is deeply misleading, as is the treatment it receives from major news outlets.

Emily Jashinsky is a commentary writer for the Washington Examiner.