Protesters hold signs and chant in Thomas Paine Plaza to protest President Trump's visit at a GOP retreat in downtown Philadelphia on Thursday. (Bryan Anselm/For The Washington Post)

The rally didn’t start until 11 a.m., but Jackie Hamilton and Barb Beattie had shown up to the downtown plaza by 9:45 a.m. Planning to march in support of the Affordable Care Act, the retired schoolteachers donned attire that they sensed, wearily, would get a lot of use over the next four years.

“Ready?” asked Beattie, 68, putting on the pink knit hat she’d acquired for the Women’s March on Washington just days earlier.

“I feel like we’re being stirred up,” said Hamilton, also 68, adjusting the pink sash she got at the same place. “Trump is stirring us up and distracting us with all of his — whatever — and meanwhile Congress . . .” She trailed off. “I’m so angry. I can’t believe we’re having to deal with all this stuff. Still. Again.”

Several thousand protesters converged Thursday in Philadelphia, hoping to have their voices heard by President Trump and Republican members of Congress, who were meeting in a hotel blocks away to plan their legislative agenda for the coming months.

Less than a week after Trump’s inauguration inspired demonstrations — notably, the millions of marchers who descended on Washington and cities worldwide to protest his presidency — the Philadelphia gathering seemed to signal a new era of what could turn out to be perpetual protest.

And marching — an age-old protest strategy — has taken on new meaning as a tool against a leader who is uniquely preoccupied by numbers and size.

The crowd that gathered in Thomas Paine Plaza focused on one of the most aggressive measures of the new Republican administration — an effort to repeal and replace the Affordable Care Act. Signs at the rally protested this plan but raised other angers as well, residual and new: “Scientists Against Trump.” “Not a Journalist, and I want to see your tax returns.” “Stand Up Against Alternative Facts.”

Organizers said that about 5,000 people showed up in response to their invitation to try to disrupt the new president’s first jaunt away from the White House. The protests appeared to unfold peacefully, with no reports of widespread arrests or clashes.

Hamilton and Beattie found a patch of concrete and tried to hear the speakers from One Pennsylvania, the coalition that had organized the rally.

“I’m honored to be here for the resistance,” the first speaker yelled. “Who else is here for the resistance?”

Beattie and Hamilton yelled back that they were there for the resistance, along with the other several thousand attendees. Beattie said she was also there for her daughter, who had gone from being a healthy 33-year-old to an invalid with rheumatoid arthritis in a matter of weeks, and who was covered by the Affordable Care Act. Hamilton was there because each passing day of Trump’s presidency, in her opinion, seemed to bring a new outrage, one tumbled on top of the other. The nominee for secretary of state terrified her. The nominee for secretary of education offended her public-school sensibilities.

The country seemed to be spinning out of control, and the only outlet for Beattie and Hamilton’s rage was to protest, and to call their senators, and to follow the action steps sent to their inboxes every day.

“The thing about marching is we get there, and — how much are we really affecting them?” asked Robin Gauri, a mother of young children who was standing next to Hamilton and Beattie. The first protest she’d ever attended had been the Women’s March on Saturday; this was her second. “Are they even hearing us?”

“I know, but I would rather march,” said her friend Judith Kaplow-Applebaum, a protest veteran of several decades. “I would rather march, even if we don’t know what it’s doing, even if it takes a long time. You should see — up until last week, the crowds at Philadelphia protests were minimal. Now, after him,” she said, pausing to gesture to the packed plaza, where attendees spilled down side streets. “I would rather march.”

One of the organizers on a loudspeaker announced that the rally would begin to move down the streets of Philadelphia’s Center City, toward the hotel where the president might hear them.

“I just got a news alert,” Beattie said, showing her phone to Hamilton. “The Mexican president just canceled his visit with Trump.”

They marched.

A few minutes later, Beattie got another one and read it out loud: “The State Department’s entire senior management team just resigned,” she said.

They marched.

Far ahead of them, the march had lurched to a stop. “Is this it?” Hamilton asked, craning her neck. “Is this where Trump is?”

“He’s behind that building,” the man next to her said. “He’s in the Loews hotel, but they blocked it off with garbage trucks. We can’t go any further.”

Another chant broke out from the head of the crowd. “The people united,” the caller began.

Cannot be divided,” Hamilton and Beattie joined in automatically. Hamilton yelled louder on the second round. “The people united cannot be divided.

Inside was the man they couldn’t get to, planning things they didn’t want to imagine. They were still angry. They were still so angry and scared.