The Wall Street Journal doesn’t give PolitiFact a grade, but one suspects it wouldn’t even reach the level of “half true”:

So the watchdog news outfit called PolitiFact has decided that its “lie of the year” is the phrase “a government takeover of health care.” Ordinarily, lies need verbs and we’d leave the media criticism to others, but the White House has decided that PolitiFact’s writ should be heard across the land and those words forever banished to describe ObamaCare.
“We have concluded it is inaccurate to call the plan a government takeover,” the editors of PolitiFact announce portentously. “‘Government takeover’ conjures a European approach where the government owns the hospitals and the doctors are public employees,” whereas ObamaCare “is, at its heart, a system that relies on private companies and the free market.” PolitiFact makes it sound as if ObamaCare were drawn up by President Friedrich Hayek, with amendments from House Speaker Ayn Rand. …
PolitiFact’s decree is part of a larger journalistic trend that seeks to recast all political debates as matters of lies, misinformation and “facts,” rather than differences of world view or principles. PolitiFact wants to define for everyone else what qualifies as a “fact,” though in political debates the facts are often legitimately in dispute.

And that’s precisely why they wish to define “facts.” For the same reason that the left typically strives to define its preferred cultural innovations in terms of “science.” Facts and science are supposed to be the objective foundations on which our opinions are built; treat one side’s opinion as a lie, and its structure will necessarily lean the other way.
The journalists behind PolitiFact across the country may not be self-aware purveyors of malicious propaganda, but the “lie of the year” (like the local variation on the Social Security Ponzi scheme question) proves them unable to control their rhetorical experiments for their own opinions.