You only have to spend a few minutes in Dilworth Park to see what a people magnet it has become since the Center City District completed a dramatic, $55 million makeover two years ago. Besides regular attractions, like the cafe and sparkling fountain, there is something special going on 186 days a year - that's every other day - ranging from concerts and farmers' markets to bocce tournaments and Lupus Awareness booths.

Everything, that is, except demonstrations.

You read that right. In response to a formal request I submitted to the Kenney administration, a spokesperson confirmed that the city's Office of Special Events has not issued a single protest permit in the 22 months since Philadelphia's great public living room reopened under CCD management - a period of extraordinary public discontent that brought the rise of the Black Lives Matter movement, terrorist attacks, and police killings.

That record won't change when the Democratic National Convention pulls into town next week. Though some 35,000 protesters are expected to descend on the city, they will have to go elsewhere to exercise their First Amendment rights, at least if they want to do so legally. Not one group was able to secure a protest permit for convention week because Dilworth was booked solid months ago, with vendors and entertainers, as well as a tent for a nomination-watch party.

The CCD manages the space, but it is the city that vets all event applications, and it won't approve a demonstration if anything else has been scheduled. Unfortunately, when I asked city officials how many applications had been rejected over the last two years, I was told the special events office was "swamped" and it would take several weeks to assemble the information.

But you can contrast the absence of political debate in Dilworth with the scene in Cleveland during this week's Republican National Convention. Its newly redesigned downtown plaza, Public Square, has played host to an outdoor people's convention, with dozens of peaceful protests competing for attention. That noisy soapbox coexists with Public Square's other attractions, including a splash fountain similar to Dilworth's.

Philadelphia protesters will have to go farther afield to express their views. The closest they will be able to get to City Hall are the cramped aprons on the north and south sides. Several protests are also planned for the aptly named Thomas Paine Plaza - the one with the game pieces - across the street.

Named for the philosopher and professional agitator, Paine Plaza is not a bad substitute venue for displays of free speech, but it's no Dilworth. As the doorstep to City Hall, the seat of government power, and a crossroads where Philadelphians of all sorts collide, Dilworth's symbolic meaning is unique. With City Hall's familiar beaux arts facade as a backdrop, it is a tailor-made stage.

That's the role the three-acre granite expanse has played in the life of the city ever since its completion in 1977. It was where ACT UP protesters gathered when they were desperate to bring the AIDS crisis to wider public attention in the early '90s. Antiwar activists protested the Iraq invasion there in 2003, and education advocates begged for increased school funding in 2011.

Even organizers of marginal causes knew they could get a hearing in Dilworth. In 2006, Philadelphia cabdrivers massed on the plaza to denounce a new rule requiring them to install GPS devices in their cars. (OK, not every protest is on the right side of history.) And on those rare occasions when our sports teams didn't embarrass us, it was where we went to cheer them on with pep rallies.

The last time a major protest was held in Dilworth Park was before the renovation, in fall 2011, when Occupy Philadelphia was hunkering down for what became a 55-day demonstration to highlight the plight of America's have-nots. The sleep-in ended when Mayor Michael Nutter ordered Occupy's tents cleared from the plaza. Soon after the dust settled, Dilworth's management was transferred to the Center City District, which raised the money to make the renovation possible.

The new version of Dilworth, designed by Olin and KieranTimberlake, was intended as a flexible space that can support a variety of events. At the center is a flat, inground fountain that can be turned off to install a stage or ice rink or farmers' market.

So, how is it possible that this spiffy new surface has not been able to accommodate a single legal protest in two years?

It's true that several small protests have invaded Dilworth Park in the last two years, but none had obtained permits. In each case, the city and CCD allowed those groups to make their voices heard. But being tolerated is not the same as knowing you belong. Nothing dramatized the disconnect like the moment when Black Lives Matter activists had to shout over the rumble of the skating rink's Zamboni during a protest to mourn the death of Michael Brown in Ferguson, Mo.

It's entirely possible many activists don't bother to apply for demonstration permits. But it's also possible the heavy scheduling has scared some away. The CCD, a private business group, submits its events schedule as much as a year in advance.

Protests, by contrast, are spontaneous occurrences. Then, so are sports celebrations. Yet Villanova somehow managed to secure a permit in April to hold a public bash there after its basketball team won the national college championship.

After Cleveland's exemplary openness, the absence of legal protests in Dilworth during the DNC will be glaring. At least one group had its application rejected for the DNC because Dilworth was booked, Mary Catherine Roper of the American Civil Liberties Union of Pennsylvania told me. Ironically, the same thing happened during the Republican National Convention in 2000, for the same reason.

Ajeenah Amir, the city's deputy communications director, said it was not the city's policy to discourage protest in Dilworth Park. But that does appear to be the result.

The city, to its credit, seems to be troubled by its record. In an email, Amir wrote: "The Managing Director's Office agrees that it's unusual that no demonstration permits have been granted to date, so we intend to look at all previously submitted permits to verify that they were in fact denied because of preexisting programming."

Good for them. But it won't be enough to justify the rejections as the result of conflicts.

As more public spaces are forced to rely on fee-paying activities to support their upkeep, the pressure to book moneymaking events has intensified. See: Franklin Square and the recent Chinese Lantern Festival.

The Center City District deserves credit for transforming Dilworth Park from a derelict and unloved park into a people-pleasing hive of organized activity. But it would be a terrible thing if all those entertainments crowded out space for the real basis of public life: free speech.