I happened to be eating a donut when I went to see to a left-liberal-vegetarian-health-fanatic friend recently, and this gave me an opportunity to present the one negative metaphor about Obama's economic program that my friend just might find at all persuasive: It's like this donut -- it gives a brief burst of energy, but the longer-term effects include calcification of the arteries.
For better explanations of the deepening economic sclerosis, I recommend these (related) pieces by Will Wilkinson and Jim Manzi.
