Dave Weigel will have more on the numbers at the heart of the specific claim in a little bit, but here's the video that is likely going to be making the rounds for the next few days, if not longer.
In it, Mitt Romney is captured on tape telling donors at a private fundraiser earlier this year that his campaign won't focus on those Americans who don't pay income tax—a demographic that the GOP hopeful says will vote en masse for President Obama no matter what because they are looking for a government handout.
Here's the quote in question as can be heard in the video that was obtained by Mother Jones: Romney says:
There are 47 percent of the people who will vote for the president no matter what. All right, there are 47 percent who are with him, who are dependent upon government, who believe that they are victims, who believe the government has a responsibility to care for them, who believe that they are entitled to health care, to food, to housing, to you-name-it. That that's an entitlement. And the government should give it to them. And they will vote for this president no matter what … These are people who pay no income tax. ... [M]y job is not to worry about those people. I'll never convince them they should take personal responsibility and care for their lives.
The most natural immediate comparison appears to be Barack Obama's now infamous "guns and religion" quote from his own private fundraiser back in 2008, although it remains to be seen if this one will have the same type of staying power.
[UPDATE: Romney called an impromptu presser late Monday to address the mounting criticism. While the GOP hopeful admitted that the comments were "not elegantly stated," he largely stood firm behind the idea he says he was trying to express.]
Here's the video: