At the end of this month, hundreds of Philadelphia-area protesters plan to stage a “Ninja Run” at the U.S. Immigration and Customs Enforcement field office, sprinting around the Center City building in the hope of disrupting deportation operations.

It will be at least the seventh local protest in as many weeks — including “Rise for Refuge” on Aug. 4, when 300 people marched to City Hall to support refugees, and “Lights for Liberty,” where 500 or more blocked streets before rallying at ICE’s doorstep on July 12.

Collectively, the demonstrators denouncing the Trump administration’s treatment of immigrants must have marched a thousand miles — and thousands more during the last two years.

But have they gotten anywhere?

White House rhetoric and policies have only toughened, as President Donald Trump works to limit immigration and harden enforcement at every turn. Fifteen months before the 2020 election, there’s no sign that big public demonstrations in Philadelphia and around the nation have even nudged the president in a new direction.

Some local immigrant advocates say it’s true that the protests can seem to have had little impact on policy — but no one expects them to trigger immediate change.

“The protests are one component of an overall strategy,” said Sundrop Carter, executive director of the Pennsylvania Immigration and Citizenship Coalition, which routinely leads and joins in pro-immigrant actions. “It’s the physical and public manifestation of the work that’s going on on a day-to-day basis. … It isn’t like one-to-one, like protest equals change, but it is one of the most direct ways for people to voice their concern.”

Consider the Civil Rights Movement of the 1960s, she said. The Aug. 28, 1963, March on Washington for Jobs and Freedom — where an estimated 250,000 heard the Rev. Dr. Martin Luther King Jr. declare, “I have a dream” — did not deliver passage of the landmark 1964 Civil Rights Act on its own.

But that march was the most visible aspect of a larger, layered strategy that included legal efforts and meetings with members of Congress, she said.

Blanca Pacheco, co-director of New Sanctuary Movement of Philadelphia, said the Philadelphia-area demonstrations are producing more than sore feet.

They generate publicity, which is crucial to creating awareness. They provide an example for potential new allies, and space for them to get involved. And they build community and alliance, generating a sense of power and possibility among people who share the same political and social-justice aims.

“National change doesn’t always happen in D.C.,” Pacheco said. “It happens locally first, and then it expands.”

Empirical evidence on the effectiveness of protests is contradictory, with some academic studies finding that public actions can engender institutional change, and others showing mixed results.

One big caveat: It’s hard for people to know whether a protest movement is driving transformation when they’re in the middle of it.

“Societal change occurs slowly over long stretches of time, and protests, media coverage, networks on-the-ground, culture, policy, and politics all work together,” said Jason Steinhauer, director of the Lepage Center for History in the Public Interest at Villanova University. “It takes a while to truly assess the successes or failures."

What is believed to be the largest single protest in American history took place the day after Trump’s inauguration, when the Women’s March drew more than 3 million into the streets of cities around the country on Jan. 21, 2017.

Did it make a permanent difference?

“Social movements can not only beget institutional change, but also long‐run, attitudinal change,” Harvard University doctoral candidate Soumyajit Mazumder wrote last year in the American Journal of Political Science.

He used data from 150,000 survey respondents to show that white people in counties that experienced historic civil-rights protests were more likely to support affirmative action, and less likely to harbor racial resentment against African Americans.

But scholars writing in the Quarterly Journal of Economics in 2013 were much less certain. Movements from the French Revolution to the Arab Spring have been associated with political change, they said, but it’s unclear whether they actually caused it.

In the Philadelphia region, it can seem like pro-immigrant demonstrations are happening every week. Candlelight vigils in South Jersey. Toddlers at a “Melt ICE” playdate. Senior citizens confining themselves in faux “cages” on Independence Mall.

The planned Aug. 31 Ninja Run is also known as a Naruto Run, named for a Japanese anime character often shown sprinting with his arms splayed behind him.

“It makes a difference,” Germantown retiree Virginia Rice said as she took part in the Lights for Liberty rally. “It’s hard to see at the time that you’re making a difference, but I think it matters.”

She marched against the Vietnam War, often cited as a clear example of protest impacting policy. But even widespread demonstrations did not quickly end the conflict. The National Mobilization Committee to End the War filled the nation’s capital with demonstrators on Oct. 21, 1967, but the war ground on for eight more years, ending in April 1975.

The modern power of public protest, PICC’s Carter said, is proven by the efforts of those in government to stop it.

Since November 2016, when Trump was elected, 35 states have considered a hundred bills to restrict the right to protest, according to the International Center for Not-For-Profit Law in Washington, D.C. Sixteen of those bills were enacted, and 69 were defeated or expired.

In the aftermath of oil-line protests at Standing Rock, N.D., legislators considered a bill to shield motorists who ran over demonstrators with their cars. That bill failed. But North Dakota and at least six other states enacted new penalties for people who demonstrate near oil and gas pipelines, with Louisiana ready to send trespassers to prison for up to five years of hard labor.

In Pennsylvania last year, the Berks County commissioners considered — and under pressure excised — ordinance language that would have stopped people from gathering or putting up signs on the roads around a controversial migrant-detention center.

“If protest was not an effective strategy, there would be no need [for a government official] to do that,” Carter said. “The reason to do that is, ‘This is a powerful way for people I disagree with to make themselves heard.’ ”