In California, overhaul advocates in caravans from around the state descended on the Bakersfield office of the No. 3 Republican in the House, Rep. Kevin McCarthy. In Colorado, they marched in the streets. Religious leaders told GOP lawmakers stories of families torn apart by deportation. Business executives made the case in economic terms. One group even lobbied Donald Trump.

To a degree, it worked: Several Republican lawmakers have recently tipped to their side, which advocates say is building momentum.

But privately, both backers of revamping the nation’s immigration laws and top Republicans say 500 or so events did little to alter internal House GOP dynamics. The prospects for significant action when Congress returns Monday appear increasingly dim.

With just nine legislative days planned in the House in September, GOP lawmakers are expected to focus on whether to authorize a strike against Syria and then turn to the battle over the federal budget, which is likely to consume their schedule.

House Republicans remain deeply divided on immigration, and they see little urgent need to resolve it. Some have even begun to talk about pushing the debate well into next year so the primary elections will be behind them before any vote.

At an immigration forum last month in Arizona, Republican Sen. John McCain, a chief architect of the sweeping Senate-passed immigration bill, urged his party to tackle the issue this fall.

“It will be a very critical time in the life or death of this legislation,” McCain said. “It’s very important that we try and act before the end of this year, as we move into next year and an election season.”

House Speaker John A. Boehner (R-Ohio) may make room for a floor debate on several Republican-backed immigration bills in October or November. But his Republican majority remains torn over the centerpiece of any compromise with Democrats — a path to citizenship for the estimated 11 million immigrants in the country illegally.

The lack of interest in immigration legislation was apparent on a recent House GOP conference call. Not a single Republican lawmaker raised the issue; they focused instead on ways to undo President Obama‘s healthcare law as part of the upcoming fiscal showdown, according to aides familiar with the private talk.

“A lot of these members aren’t feeling any pressure on immigration,” said one of the top GOP aides in the House, who asked for anonymity to discuss the situation. “Nothing has happened to provide any momentum toward getting something enacted.”

That suggests how hard it will be to shift the GOP’s long-standing opposition to citizenship for people in the U.S. illegally. Republican leaders say they believe a course correction is necessary to improve the party’s standing with Latino and other minority voters. But many rank-and-file Republicans remain wary.

A number of Republican lawmakers represent primarily conservative, white districts, and are just now learning about the complex and politically charged topic.

“They’re finding their voice,” said Frank Sharry, a veteran immigration advocate with America’s Voice. “Will those Republicans who want to get reform done, who want to change the GOP — can they get to yes?”

A delay poses political problems for Republicans, leaving the party still struggling to achieve its stated goal of attracting Latino voters, many of whom view an overhaul of immigration rules as crucial.

“Time is not their friend,” Eliseo Medina, secretary-treasurer of the Service Employees International Union, said of Republicans. The union has many Latino members and is pushing for immigration law changes.

Medina said Boehner risked taking the GOP in the direction of former California Gov. Pete Wilson, who won reelection in 1994 on a tough anti-illegal-immigration platform but left the state GOP deeply wounded.

“The price of doing nothing is not always nothing,” Medina said. “We will be marching to the polls with a report card in hand and a message: If they want us to vote for them, they have to vote for us first.”

Boehner has complicated matters by promising to consider only legislation that is supported by a majority of his GOP conference. That high hurdle means it is possible that no bills will come to the floor.

Even a relatively popular bipartisan measure to beef up border security from Rep. Michael McCaul (R-Texas) could run into resistance. Some Republicans have vowed to block any immigration bill in the House.

At the same time, the ability of the unusually broad coalition of advocates to outnumber the scant opposition this summer shows how much attitudes have changed. The last attempt to overhaul immigration laws, in 2007, withered in the face of an intense backlash. But advocates have prepared for the long haul.

“I think it looks better than any time I’ve seen it for a while,” said Alex Nowrasteh, an immigration policy analyst at the free-market Cato Institute.

At a recent town hall meeting in a fire station in Greer, S.C., Rep. Trey Gowdy, a Republican first elected in 2010, surveyed his constituents and learned they were skeptical of government’s ability to fix the problem. Many also do not view it as urgent. But they do think conservatives should offer solutions.

“What I’m hearing people say is, ‘Look, Gowdy, we might eventually want to have that conversation with you, but we just don’t trust the front part.’ And I get that,” he said. “So that’s where we are.”

lisa.mascaro@latimes.com