The dictators in Beijing can hide no more. They either have to stay out of the way and let Hong Kong march towards democracy as they promised, or they have to come out and crush Hong Kong people’s aspiration and show the world China is determined in going against history.

On Sunday, Hong Kong had its third huge demonstration in two years. Organizers claimed the turnout was 250,000, while the police said it was 63,000. The key lies not in the exact numbers but the fact that it was way beyond everyone’s expectation.

After the previous two marches, in which roughly 500,000 people participated on July 1 in 2003 and 2004, Beijing pretended that Hong Kong people were marching for something other than democracy. But now, all the excuses are gone. Hong Kong’s economy is expected to grow for 7% this year; unemployment is at 5.3%, a four-year low; highly unpopular chief executive Tung Chee-hwa was replaced by a more competent Donald Tsang; and SARS has not resurfaced.

This time, marchers have one thing in mind this time: we want democracy, and sooner rather than later. The crux of the matter is: when can Hong Kong people elect their chief executive and the whole legislature by “universal suffrage,” which is stated in the Basic Law, Hong Kong’s constitution drafted by Beijing, as the “ultimate aim?” Beijing basically says “Not now. Later. Shut up.” Hong Kong people respond, “Give us a timetable then. We have waited long enough.” For 20 years indeed.

A drop of democracy was first introduced into the Legislative Council in 1985 by the British, when a few seats elected by the functional constituencies were returned in the otherwise totally-appointed body. Over the years, the numbers of directly elected seats have been increasing while the indirectly elected and the appointed ones have been dropping, from 18 vs. 42 in 1991, 20 vs. 40 in 1995, 24 vs. 36 in 2000, to 30 vs. 30 in 2004. The next election, to be held in 2007, could have been the earliest possible time for the whole 60-seat body to be elected democratically, which is, again, stated in the Basic Law.

What the Hong Kong government proposes for 2007 instead, under strict “guidance” by Beijing, is to increase the numbers of democratically elected seats to 35 from 30 while the undemocratically-selected seats would not be decreased as the trend has been going, but increased to 35 from 30 as well. The chief executive, currently selected by a 800-member committee, would be returned by 1,600 people in 2008. Who can blame the people of Hong Kong for rejecting such a window-dressing plan, which is scheduled for a vote in the legislature on December 21?

Beijing, sensing that the proposal won’t be able to gain the two-third majority support in the chamber that is required, was desperate to try to show a more conciliatory face before the march. First, two astronauts from China’s second manned spaceflight, who are considered national heroes, were dispatched to Hong Kong last week to boost nationalism. Second, many pro-democracy lawmakers were invited to meet a senior official in Shenzhen, a city north of Hong Kong, two days before the demonstration. Third, chief executive Tsang unprecedentedly went live on television to appeal for support from the people.

None of these tactics worked. Dictators are dictators and they can’t help showing their true colors. Chinese officials at the Shenzhen meeting declared that it would be unlawful even to set a timetable for achieving universal suffrage. That might have prompted the highly regarded former no. 2 Hong Kong official, Anson Chan, to join the march, pumping even greater momentum into the movement. She said “I hope I could see universal suffrage while I am alive.”

Tsang, to his credit, echoed this view and said after the march, “I am 60 years of age. I certainly want to see universal suffrage taking place in Hong Kong in my time. My feeling and my wish is the same as most other people participating in the rally today.” He admitted that there’s little room for him to change the proposal but said he will see “what I can do to perfect the package” within the little room that he has.

I’m afraid recent records don’t offer much hope for Beijing to give an inch to the growing thirst for democracy in Hong Kong. After the first march in July 2003, the then Tung administration was forced to shelve a piece of repressive anti-subversion legislation. That was the very first time for the brutal Chinese Communist Party to have backed down to a peaceful demonstration in its history (remember what happened in Tiananmen Square in 1989?). Beijing returned the favor by vetoing universal suffrage for Hong Kong in April 2004. After the second march in July 2004, a protest against Beijing’s veto, Beijing in April 2005 handed down another unpopular verdict regarding the length of Tsang’s term as the chief executive.

The State Department on Monday reiterated the U.S. support for democracy in Hong Kong. Adam Ereli, the deputy spokesman, told us, “We believe that it’s important to achieve universal suffrage in Hong Kong as soon as possible, that the people of Hong Kong are ready for democracy and that the sooner that a timetable for achieving universal suffrage is established the better.”

Hong Kong people can march as much as they can but this alone won’t lead to universal suffrage unfortunately. Firmer support from the U.S. would be crucial at this juncture. This administration, in particular, has no excuse for allowing democracy to be strangled in Hong Kong. Start doing so today – Deputy Secretary of State Robert Zoellick is hosting Chinese Executive Vice Foreign Minister Dai Bingguo in Washington for a two-day second session of the U.S.-China senior dialogue. Let China know the U.S. is serious by raising the Hong Kong case each and every time.

Mr. Liu is a Washington-based columnist.