The National Mall goes kitsch: America's cluttered backyard shows just how hard it is for Congress to say "no.".

Last month, several thousand people gathered on the National Mall for a "virtual groundbreaking" for a proposed memorial to Martin Luther King Jr. It's set to go up on a piece of land just off the Tidal Basin, putting it within view of the Jefferson, Lincoln, and Roosevelt memorials.

Plans are also in the works for an African-American History Museum and a memorial to President Eisenhower. Six years ago, Congress approved a half-billion-dollar "Congressional Visitors Center" on the Mall to pat itself on the back, a project now three years behind its scheduled completion and more than a hundred million dollars over budget. Some conservatives are agitating for a Ronald Reagan Memorial. It's likely that we'll also get a memorial to 9/11 and the war on terrorism.

The National Mall, originally envisioned by Pierre L'Enfant as a serene place for public celebration and quiet contemplation, is quickly turning into a kitschy amusement park of special interests. Recent additions--the FDR Memorial, the World War II Memorial, and the National Museum of the American Indian--have added clutter and pedestrian traffic, further obstructing the serene views L'Enfant intended.

The Mall presents a tidy symbol of what has happened to the federal government over the last half-century. If Congress doesn't have the backbone to turn people down when meting out a limited supply of acreage on the National Mall, you can see why the federal budget would present the same problems writ large. There's only so much space on the Mall, but there are many ways to transcend the budget's limits: deficit spending, "trust fund" dipping, tax increases.

Economists frequently talk about the problem of concentrated benefits and diffuse costs. Select groups of people with a strong interest in, for example, a federal subsidy can come to Washington and wield quite a bit of clout.

An individual congressman, then, will feel tremendous pressure from hundreds of lobbying beggars, but little from the millions of federal taxpayers who subsidize them. After all, the cost per taxpayer for most of these programs is just pennies.

Once a subsidy, program, or agency is in place, it's set in stone. Congress won't ever move to eliminate it for the same reason the program was started in the first place--each small, powerful interest group getting these benefits has much more incentive to punish lawmakers who cross them than does the average taxpayer footing the bill.

What's happened to the Mall is a tidy, tangible illustration of these problems in action. It's certainly understandable that Congress might want to add more recent figures and events to the roster of history that lines the Mall. But some citizens have come to see a slice of real estate there as a symbol of how seriously the country takes their grievances or contributions.

And it's not as if recent additions have added much in the way of ambiance. The Jefferson, Washington, Lincoln, and Vietnam memorials are simple, elegant, and poignant. The Mall's most recent additions--the FDR Memorial, the World War II Memorial, the American Indian museum--are cumbersome, expansive, and more concerned with not offending anyone's sensibilities than with remembrance or historical accuracy.

FDR, for example, said that if the nation insisted on giving him a memorial, it should be no larger than his desk. In the five decades between his death and the opening of his memorial in 1998, "no bigger than my desk" grew into a sprawling, unwieldy, 7.5-acre attempt to capture his legacy--not a bad metaphor, actually, for what's happened to the federal government since Roosevelt became president.

Likewise, the World War II monument, rushed to completion after badgering from big swingers like Tom Hanks and Bob Dole, is a clunky checklist of a memorial that overwhelms with an assault of fountains, flags, plaques, obelisks, and concrete. Designers were desperate not to offend anyone by omission, so they erred on the side of including everything--every state, every subgroup of soldier, every military branch, every theater, and every country gets a pillar, a fountain, a flag, or a plaque. Simple and elegant it isn't.

Then there's the National Museum of the American Indian, a hulking slab of stucco a stone's throw from the U.S. Capitol. Slate's Timothy Noah called it "a public service announcement" for Native Americans that has almost "no scholarly value." That was one of the kinder reviews.

The debacle that's become of the National Mall demonstrates just how difficult it is for the federal government to say "no" when interest groups-especially sympathetic ones--come calling.

Radley Balko (rbalko@reason. corn) is a senior editor at reason. An earlier version of this column appeared on FoxNews.com.