From TCS:

A reporter once asked President Reagan if he had anything to say in defense of his deficits. “No” answered Reagan, “they’re big enough to defend themselves.” Liberals howled, and conservatives chuckled, but no one questioned the premise of the question: that deficits are inherently a bad thing. The argument has always about whether the bad thing called deficits are too large and whether they will ever be paid off, not whether they can actually be good for our country. For the record the answers are: no, they’re not too big (see attached chart); no, they will never be paid off, and yes, they can be a good thing.