It is now unofficial policy at the Daily Caller (DC) for reporters to identify Politico as a “liberal publication,” a source who writes for DC told THE BLAZE. The source requested anonymity.

Since last Wednesday, no fewer than four stories (one of which was also published on the Washington Times website) by DC reporters have referred to Politico as “a liberal publication based in suburban Virginia,” “the liberal Politico newspaper” and “liberal publication Politico.”

DC began the practice after Politico published an article in which it “confirmed” the story about Michele Bachmann’s debilitating migraines, first reported by DC.

Daily Caller staff told to I.D Politico as liberal

Daily Caller Editor in Chief Tucker Carlson

“When we broke the Bachmann story, [DC Editor in Chief Tucker Carlson] was pissed that they felt the need to confirm,” the source said.

Also in Politico’s story, DC was identified as “a conservative online publication.”

“So, [Carlson] sent out an email [to staff] like, ‘from now on let’s call Politico “liberal newspaper Politico”‘,” the source said.

Since the Bachmann story, Politico has referenced DC’s reporting in at least three separate stories, none of which identified the publication as conservative (see here, here and here).

We reached out to Politico for comment on DC identifying the publication as “liberal.” The publication’s executive editor Jim Vandehei responded to THE BLAZE in an email:

“I have no clue. I know Tucker well, and feel quite confident he doesn’t actually believe we are a partisan publication. Just like our other readers, Tucker knows we pride ourselves in fairness and fact-based reporting. Perhaps it was a simple editing error in his shop.”

Carlson declined to speak on the record.

Neither Politico nor DC bill themselves as coming from the political right or left. But it is worth noting that longtime reporter for Politico Andy Barr left the publication last Monday to work for the Democratic Party in Arizona (a story DC broke). And another of their reporters left to work for Democratic Congresswoman Debbie Wasserman Schultz in Jan. 2010 before returning to Politico less than a month later.

Likewise, DC’s media reporter Jeff Poor once worked for the conservative Media Research Center, a news watchdog, and conservative writer Matt Lewis also has his own prominent blog on the site.