Public and private coexisting.

...in many other sectors of the economy, government and private offerings happily compete and coexist. Well-established government options are available as backstops for millions of Americans, especially those without the money to afford any alternative - without denying customers who want to pay more for different or better services the right to buy what they want.

There's the government option in schooling. All across America, local and state governments, with increasing involvement by the feds (thanks to George W. Bush and No Child Left Behind), educate young people. All told, it costs us about $1 trillion a year. That hasn't kept 10% of students from enrolling in private schools and growing numbers from being home-schooled. Is government doing a particularly good job with its dominant market share? No - but the point here is that America is pretty comfortable with the powerful, effectively mandated, public sector role.

There's the government option in security. This one, like education, is in many respects a government-imposed monopoly. Keeping people safe has long been considered the quintessential public sector duty. That hasn't stopped businesses and individuals from supplementing government security with their own private providers.

There's the government option in shipping, the post office. The USPS gets taxpayer funding and other advantages. But that hasn't stopped FedEx and UPS from peeling away customers by offering premium services and greater convenience. Right now, the USPS, FedEx and UPS split the overnight delivery market share with about a third a piece. Cats and dogs, living together.

There's the government option in scientific research. Government agencies dole out most of the money seeding experiments in fields from basic physics and chemistry to energy and astronomy to biology. Through the National Institutes of Health and National Science Foundation, in fact, government selects winners and losers. And by most accounts, it does a decent job.

There's the government option in travel. Amtrak has been propped up by the government for years; it competes with private sector planes and buses. Some Americans choose the train. Some choose other modes of transportation. The sky does not fall.

There's the government option in recreation. The federal government is the nation's largest land owner. National parks compete for tourism business with privately owned resorts and businesses, and attracted some 13.8 million visitors in 2008. That's a few million fewer than visit Disney's Magic Kingdom in Orlando. And don't forget government-run and funded museums, from the Smithsonian (funded by the feds) to the Metropolitan Museum of Art (whose buildings are owned and whose operations are supported by the City of New York).

There's the government option in book lending. For years, libraries have coexisted alongside brick-and-mortar and online bookstores. They offer services to those who can't or don't want to pay more. Do they make it harder for book stores to survive? Perhaps, but they're considered a true public good.

There's the government option in retirement. We call it Social Security. To many elderly Americans, it's the only thing standing between them and poverty. None of this stifles private retirement plan innovation. And public-employee pension plans, run by government officials, regularly throw their weight around the private equity markets.

And, like it or not, there's already a sizeable government option at work in health care. Medicare, Medicaid and the Veterans Administration may be plagued with problems - just like, ahem, private health care - but, each in their way, do the job...