As we are approaching the crucial third presidential debate, Barack Obama's running mate, Joe Biden, is doing what he can to help the president's campaign. While campaigning in Ohio on Monday, Joe Biden commented on Barack Obama's comment about Mitt Romney's tax plan being 'sketchy'. Biden chose to elaborate.

As vice president, it's not my job, nor am I inclined to correct the president, but in this case I am. Romney's plans aren't sketchy - they're Etch-a-Sketchy.

The Obama camp has repeatedly said that Romney's plan isn't mathematically possible, while the Romney camp maintains that it is.

[Via CNN]