I watched them stride across Cairo's bridges in their tens of thousands.

Protestors heading to Tahrir Square to join probably the largest rally yet.

"It's just a game of confidence and being stubborn," said one young man who, like the others, wants President Mubarak to quit.

This man was in his 30s. He had unkempt hair and cheap sports clothes. He did not represent the urban elite.

Yet he was as riled as the rest, dismissing as insubstantial government concessions such as a 15-percent public-salary pay rise and a committee to look at constitutional change.

"That's just talk," he snarled.

There was no shortage of protesters eager to talk to a foreign reporter.

Another man insisted government concessions are fueling not quelling the protests.

"All this happened in only ten days," he observed. "Surely we have shaken the whole regime."

The Obama administration is demanding change in Egypt that's steady and sure.

Like rolling back what critics call its police state.

There's a Groucho Marx lookalike who studies me from his car whenever I leave my hotel.

Many protesters fear Egypt's secret police are photographing the demonstrations and, if they are not reined in, will eventually confront the protesters with interrogation and jail. That's what Iran did to its protest organizers two years ago.

For now though, Egypt's security forces are taking a light touch. They want to pretend everything is fine.

As I walk into Tahrir Square I step over piles of rocks, assembled by protesters in case of further street combat. Nobody is trying to disarm them.

Soldiers are leaving unerased English four-letter insults scrawled on their tanks.

And the plain-clothes police agents who are undoubtedly mixing with the protesters are making no effort to remove banners and graffiti denouncing President Mubarak as a thief.

Several protesters are waving defaced Egyptian flags, a gesture that might normally send them to jail.

Everything seems normal.

That's the image officials want to project.

But they have a problem.

These protests are difficult to challenge because people of all backgrounds are on Tahrir Square.

There is no single leader for Egypt's government to harass or buy out.

In fact, there are very few leaders.

One, a former political prisoner named Ayman Nur, told Fox News Channel he plans to run for president.

But he said Washington needs to overcome its fear of radical change in Egypt.

"It's wrong to think that only Mubarak stands in the way of the Islamists," he told Fox. "That's a lie spread by Mubarak. And America is addicted to it."

Nur casts himself as a third force, between the iron fist of Hosni Mubarak, and the iron dogmatism of the Muslim Brotherhood.

By Fox News Radio's Alastair Wanklyn, in Cairo