My new column at Columbia Journalism Review discusses the problem of fact-checkers leaving the realm of verifiable evidence and weighing in on semantics and political process issues. Here’s how it begins:

What, exactly, is a “serious” plan to resolve the budget impasse in Congress? It’s not clear how to define adjectives like this, but that didn’t stop Glenn Kessler, The Washington Post’s Fact Checker, from weighing in with a column on Monday arguing that President Obama’s budget is “not really a plan” because Obama hasn’t offered “a sustained presidential commitment” to it, including challenging his own party and “[making] the case for overhauling entitlement programs to the American people.”

Unfortunately, Kessler’s argument is semantic, not factual, and based in his own centrist ideology—a mistake that he and other factcheckers make too frequently. Factchecking is an inherently subjective enterprise; the divide between fact and opinion is often messy and difficult to parse. As CJR’s Greg Marx argued, it is therefore essential that factcheckers like Kessler only invoke the authority of facts when assessing claims that can be resolved on evidentiary grounds, rather than straying into subjective judgments about the political process or semantic debates over terminology.

Read the whole thing for more.