If you live in Washington or just visit for a few days, you may run into the entitlement people. Some of them are former senators, cabinet officers or other previously powerful folks. Others are maverick members of Congress or agency heads, who are not in a position to set policy but are prominent enough to get noticed.

They bombard you with alarming statistics about unsustainable entitlements. The U.S. government has $43 trillion in unfunded liabilities, or $350,000 for every taxpayer. Standard & Poor’s projects that in 2012, the U.S. will lose its AAA bond rating.

Everyone listens and puts on a long face to show that they, too, are gravely concerned. The facts are indisputable, and everybody agrees abstractly that something really must be done. But then the conversation is over and most people are relieved to slip back into a different reality.

In the different reality, everybody plays by Mardi Gras rules. The norms are different, masks are worn and certain unpleasant facts fall away. Presidential candidates vow to offset the cost of health care plans through “cost savings” measures, and everybody pretends those savings are actually real. Republicans promise tax cuts and people pretend those pledges are not absurd. Democrats vow to pay for their grand spending plans by raising taxes on the rich, even though each one percent increase in the top tax rate only produces $6 billion in revenue.