Jerry Delaney listens to speakers during an Organizing for Action rally against gun violence in Chicago on April 13. (JOHN GRESS/REUTERS)

President Obama’s supporters are discovering that winning a national election is easier than winning over Congress.

Organizing for Action, an advocacy group born from the remnants of Obama’s victorious 2012 reelection campaign, has struggled in its attempts to help the president push through legislation on the economy, guns and other issues central to his second-term agenda.

The fledgling nonprofit group has spent its first four months staging rallies and generating local news coverage in an unsuccessful effort to get the Senate to strengthen background checks for gun sales.

It deployed technological efforts familiar from the 2012 campaign, collecting 1.4 million signatures on a gun-control petition delivered to Capitol Hill last week and producing a widely viewed Internet video mocking congressional Republicans for questioning humans’ contribution to climate change.

The group also raised $4.9 million through March and is awaiting an influx of cash from liberal donors connected to George Soros’s Democracy Alliance to expand its staff beyond the few dozen now on its payroll.

But despite its extensive voter-data files and White House connections, OFA has yet to make much of a mark on the nation’s political landscape. Many of its efforts have been centered in liberal strongholds and Democratic-leaning swing states, with little impact on more conservative areas.

“A real, sustained grass-roots movement — you can’t make that up in a minute,” said Marshall Ganz, a community-organizing expert and public policy senior lecturer at Harvard University. “It’s a long-term investment in grass-roots leadership.”

But OFA Executive Director Jon Carson said that while the group itself is young, many of its members are longtime political activists. “Our volunteers did not hatch out of an egg in 2008,” he said. “They’ve been fighting on issue campaigns for their whole lives.”

OFA is focused on promoting the president’s agenda to reform immigration, strengthen gun control, strike a budget deal and address climate change. Carson said the combination of OFA rallies and local news coverage is helping change voter attitudes, which in turn places pressure on lawmakers to back Obama’s legislative goals.

The group’s organizers say they are particularly focused on six states that Obama won last year but that are represented by at least one GOP senator: Illinois, Maine, Pennsylvania, New Hampshire, Ohio and Nevada. It is also targeting the red states of Arizona and Georgia, whose senators could be persuaded to back parts of the president’s agenda, group officials said. They plan to hold 500 events focused on immigration by the end of May, according to Carson.

“You drive local press attention, and the citizens out there hear about it,” he said. “That’s the combination that it takes.”

Carson pointed to Sen. John McCain (R-Ariz.), one of the few Republicans to support the background checks legislation, who stopped by an OFA rally in Phoenix after the bill was blocked in the Senate.

But McCain spokesman Brian Rogers said the group’s activities “had nothing to do with Senator McCain’s vote.” McCain stopped by the group’s rally because he “happened to spot them on the way home” from his office nearby, Rogers said.

Arizona’s other senator, Jeff Flake (R-Ariz.), has signaled a willingness to discuss a compromise with Democrats after coming under fire from OFA and other pro-gun control groups.

“Since the senator’s position on background checks hasn’t changed, it’s hard to imagine how OFA would have influenced his decision-making,” spokeswoman Genevieve Rozansky said.

Gun-control advocates, who asked not to be identified because the lobbying effort was still underway, said the group has performed better after the vote than before it.

OFA was visible last week in Washington as volunteers swarmed Capitol Hill. Pam Simon, who worked for Gabrielle Giffords in 2011 when the former congresswoman was shot in Tucson, buttonholed Flake in the lobby.

“The sense we got from him is that we’re still working on this. It’s not a closed door, so let’s engage. We said we’d love to sit down with him, look at the bill and talk about his concerns,” Simon wrote in a blog post. “The bottom line is that he knows we’re out there and he knows we’re not going away.”

OFA was formed in the wake of November’s election as an independent nonprofit group able to raise unlimited funds, and it maintains control of Obama’s massive campaign e-mail list.

What’s yet unclear is whether the group can transform support for Obama’s reelection into activism on behalf of his policy agenda. After the 2008 election, Obama transferred his campaign apparatus to the Democratic National Committee under the “Organizing for America” moniker, with notably modest results.

“My mom will do anything for the party, and more than anything for Obama,” said one former Obama campaign aide. “Is she going to host a house party about health care? Probably not.”

Some former Obama campaign volunteers said they’ve joined OFA to ensure the president succeeds, and now enjoy a greater sense of freedom. Penny North, a 64-year-old retired software consultant who worked on the president’s reelection, said she used to have to read from a script when she went door to door on Obama’s behalf. Now, she said, “we’re telling our personal stories.”

In some instances, however, the group has alienated people who otherwise support the president. OFA’s decision to target four conservative Democrats who opposed background checks, for example, has angered local party officials in their states. Alaska Democratic Party chair Michael Wenstrupwrote a letter to OFA last week asking the group to “cease its attacks on Democratic senators immediately.”

Wenstrup said in an interview that OFA has a “rather small” impact in his state because Obama “did not really campaign in Alaska.” But he said the decision to target Sen. Mark Begich (D-Alaska), who is up for reelection next year, with phone calls and e-mails to state residents criticizing his no vote on background checks is counterproductive.

“OFA would be better off targeting Republican senators in Midwest states and in Eastern states than trying to punish Senator Begich,” Wenstrup said.

The group has also gone after Sen. Heidi Heitkamp (D-N.D.), who opposed the bipartisan background checks bill, with similar calls. Chad Oban, executive director of North Dakota’s Democratic-NPL Party, said he would have preferred if OFA had poured more resources into the state before the vote, rather than afterward.

Carson, for his part, said people shouldn’t be surprised that OFA was unable to mobilize a major number of voters in red states represented by Democrats.

“We’ve got supporters everywhere,” he said, “but we’ve never claimed our major strength is in a place like North Dakota or Alaska.”

Tom Hamburger contributed to this article.

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