Republican presidential candidate, former Massachusetts Gov. Mitt Romney boards his campaign charter plane in Newark, N.J., Friday, Sept. 14, 2012. (AP Photo/Charles Dharapak)

WASHINGTON (AP) — President Barack Obama's campaign is seizing on a video in which Republican Mitt Romney says that almost half of American voters "believe that they are victims."

Obama campaign manager Jim Messina says Romney's comments are shocking. Messina says it's "hard to serve as president for all Americans when you've disdainfully written off half the nation."

The website of the magazine Mother Jones posted a video of Romney's comments from a private fundraiser. When the comments were made and where are not clear.

In the video, Romney says that 47 percent of voters support Obama. The Republican presidential nominee says that those people are dependent upon government and believe they are victims.

The Romney campaign did not immediately respond to requests for comment.