In the days after Donald J. Trump’s electoral victory, thousands of people revived the grass-roots movement that opposed his first term in office.

Marchers in Manhattan took over streets carrying a block-wide banner that read, “We Won’t Back Down.” Activists in Los Angeles and Chicago decried Mr. Trump’s abortion and immigration policies and vowed to descend on Washington to protest his inauguration in January.

But participants noted that Mr. Trump had not appeared to be swayed by protests, petitions, hashtag campaigns or other tools of mass dissent. Many have been calling for a fresh playbook.

“I thought the first women’s march would be a turning point,” said Laura Bartek, a 45-year-old nurse from Virginia, referring to the protest — with nearly half a million people — that took place after Mr. Trump’s 2017 inauguration.

“To be here eight years later with these signs,” Ms. Bartek said during a recent protest in Washington, “it breaks my heart.”

“I keep getting emails to sign petitions,” said Leslie Mac, a digital strategist and communications expert who works with grass-roots organizations. “These people coming to the White House don’t care about petitions. They don’t care how many people sign them. They don’t care what they say.”