Why are the Republicans calling the Affordable Care Act a "Job-killing law", even when it's been endlessly proven that that's a lie?
Well, Jay Bookman called it: they're doing it because they know that it doesn't matter if it's a lie. The point is repetition and association. They know that even people who don't believe you will tend to assume that you must have a point if you saying something over, and over, and over again. They also know that the most important thing to Americans is unemployment, that the media will give "equal time" to them no matter how much of a mountain of shit they're peddling, and that Obama will "meet them halfway" no matter how out to lunch they are.
So they're going to keep lying and everything the don't like a "job killer" over and over again. Because truth is meaningless when repetition will hold the day.