In a November ad for their special series ‘Fox News Reporting: The Challengers for 2012,’ Fox News promised ‘unrivaled access’ to ‘the GOP’s top White House contenders.’ Such access, however, isn’t hard when correspondents just have to walk down the hall.

That Fox News helps Republicans get their message across to their conservative base — long documented and publicly acknowledged by Republican officials — is nothing new. But what’s unprecedented is the level of influence one news organization can exert on a party’s presidential primary, and the rest of the media’s coverage of that primary, by simple fact of who is on its payroll.

Fox News employs five Republicans considering runs for the GOP nomination: Sarah Palin, Mike Huckabee, Newt Gingrich, Rick Santorum and John Bolton. All five regularly appear on the network through exclusive contracts and all five have used their employment to position themselves for their respective possible runs.

Take the cases of Rick Santorum and John Bolton — two potential candidates who have so little chance of winning the nomination that Fox didn’t even include them in their twelve challenger profiles.

Both would largely be out of the public spotlight if not for their Fox News contracts, yet Santorum — […]