We are in a Recession. Anyone running for office is attempting to persuade the electorate that they can create jobs. One way to persuade others of ones ability to create future jobs, is to provide their resume that they have created jobs in the past.
That's what Romney is attempting to do. We are in a Recession and because a portion of the population is unemployed, he is attempting to persuade them to vote for him because he will create additional jobs. And Romney attempts to back his statements up with his control of BAIN. But when Bain is reviewed, it's obvious that it hasn't created jobs.
That's why Newt is calling him out. Romney has presented his background at Bain as a job creator which is False. It's basically that Romney has LIED on his own Resume.