The political season brings out the worst in many, but it's still surprising that some journalists are reliving the good old days when the media claimed a monopoly on truth. Decades ago Walter Cronkite could sign off his CBS News broadcasts by declaring from on high, "And that's the way it is." Journalists can no longer claim that only they know the way it is.

Reporting as "fact checking" might have started as a check on outright falsehoods, but it has morphed into a technique for supposedly nonpartisan journalists to present opinion as "facts." The credibility of reporting has enough problems without claiming objectivity while practicing subjectivity. Not when anyone with an Internet connection can discover the difference.

It's important to distinguish between true untruths and pretend untruths. For example, both the Obama and Romney campaigns deserved to be called out for the untruths of running advertisements clearly quoting each other out of context.

But cheerleaders for a more aggressive definition of "fact checking" have a different agenda. Justifying journalism that takes sides, New York University professor Jay Rosen claimed in his PressThink blog that Republicans are pursuing a "post-truth strategy in electioneering." Rem Rieder, editor of the American Journalism Review, posted an article last week praising the media's "aggressive" fact checking of the Paul Ryan acceptance speech as a "watershed moment." The Week magazine captured the braying of the media pack in a headline: "The Media Coverage of Paul Ryan's Speech: 15 Euphemisms for 'Lying.'"

Since the Republican convention, there's been bipartisan fact checking of the fact checkers. Mickey Kaus, a Democrat who ran for Senate in California in 2010, posted an item on his blog last week on "why the Fact-Checkosphere is failing," in which he cited "the ease—rather, the constant temptation—of presenting debatable policy issues as right/wrong fact issues." He wrote that when journalists claim that a candidate has lied, it "opens up a giant sluice for the introduction of concealed bias, especially when the 'facts' are fed to the fact-checkers by the competing campaign."