Here's a piece of advice for the president who will be chosen tomorrow: Take a walk around your White House.

Yes, both candidates have lived in Washington for some time now. But how closely has either of them looked at the core of their city in the past few years -- at how ugly it has become?

The National Building Museum recently reopened an updated exhibit, "Washington: Symbol and City." It's a fine survey, but the brochure for it contains the following lie: "Today, the revered Capitol and White House, the stately offices of government, the iconic monuments and museums, and the sweep of the Mall and the city's many public parks all evoke the ideals of democracy in the 21st century."

Nobody who has walked anywhere around the White House, where George Bush has lived for the past four years, or the Senate, where John Kerry has worked for the past 19, could imagine that the ideals of democracy are being evoked. Both neighborhoods have become warrens of chain-link fences, ugly guard booths, bollards, flak-jacketed security men, closed streets and sidewalks, and public land confiscated and converted into parking lots for the well-connected.

What is evoked is fear and self-dealing.

After they shut Pennsylvania Avenue to traffic, you could still drive past the White House on E Street. No more. After they fenced off the pleasant alley between the White House and the Treasury, you could still stroll down the sidewalk on the Treasury's east side. No more. Not so long ago you could climb the steps on the west side of the Capitol, sled down the hill beneath them, wander undisturbed back up the hill and across to the Library of Congress. No more, no more, no more. Near the White House as on Capitol Hill, every time you turn around, the satraps of security have gobbled another piece of what used to belong to all of us. No hearings, no debate, no appeal: just another convenient parking area for White House aides or Senate staffers.

Everyone understands the world is dangerous. No one is advocating a return to the days of Andrew Jackson, when people could wander off the street into the White House to hack off pieces of a giant block of cheese someone had sent to the president; nor to the post-Civil War days, when newspapers complained that the White House was within rifle shot of dozens of bordellos and bawdy houses to the southeast. Tourists don't expect to try out the president's chair, as they could in Taft's time when he was out of the building, or wander the White House grounds, as they did right up until Pearl Harbor. They understand that timed passes and Social Security numbers and metal-detecting gates are part of the tourist experience in Washington.

But someone has to say enough. Three years ago, when writing about the "temporary" security barriers imposed after Sept. 11, I talked to Daniel Patrick Moynihan, then a former senator but still a patron of Washington's renaissance, with an office in the Woodrow Wilson International Center on Pennsylvania Avenue.

"Where's the balance? What's the worst that can happen? You blow up the Woodrow Wilson Center? You could build another," he said. That may sound irresponsible, but no one was more responsible for the rebirth of Pennsylvania Avenue and the construction of the Ronald Reagan trade building housing the Wilson Center than Moynihan. He loved them. But he loved something more, namely the openness that must be the hallmark of a working democracy.

In the intervening three years, some progress has been made toward reopening Pennsylvania Avenue, at least to pedestrians, and building a low wall around the Washington Monument that may not be unattractive. But for every torturous step forward, somewhere else another street is closed, another block seized, another hundred feet of hideous fencing unspooled. And once a street is closed, it does not reopen; no one dares confront the security bureaucracy, knowing that if a bomb does go off, any memo favoring access will be waved as an indictment.

Only one person can stand up to that inexorable logic of embattlement. So, congratulations, Mr. President-elect. Now go take a walk.