DANVILLE, Ky. (AP) — Republican Paul Ryan says there aren't enough rich Americans to tax to pay for all of President Barack Obama's spending.

Ryan tells viewers of the vice presidential debate, quote, "Watch out, middle class. The tax bill is coming to you."

Ryan says he and Mitt Romney want to give Congress a framework for taxes that involves lowering rates by 20 percent. He says he guarantees that can be paid for by closing loopholes, mostly on the upper class. But he isn't saying which loopholes he'd close.

Vice President Joe Biden says the only way to pay for Romney's plan is to raise middle-class taxes. He says Republicans insist on needless tax cuts for the rich and are holding hostage middle-class tax cuts that Obama wants to make permanent.