Protesters from United We Dream stage a sit-in at the state office of Senate Majority Leader Harry Reid, D-Nev., on Capitol Hill in Washington Sept. 9, 2014. Dreamers, undocumented immigrants who came to the United States as children, are upset with President Barack Obama's decision to not act on immigration reform until after Novermber's midterm elections. (J. Scott Applewhite/AP)

Less than a month after President Obama announced he would delay using his executive authority to reform immigration laws, there is evidence that the decision is doing exactly what he hoped to avoid: hurting Democrats.

Activists in key states say it is increasingly difficult to register would-be Latino voters who would vote for Democrats because of unhappiness over the decision. Poll numbers for Obama and Democrats have also dropped further among Hispanics than the population at large. One group has even launched a campaign against four Democratic senators who backed a GOP proposal to bar Obama from taking any executive action on immigration.

“The president has not helped us,” said activist Leo Murrieta, 28, who is working to register Latino voters in Colorado for Mi Familia Vota. “People are disappointed. They wanted action, they wanted activity, they wanted movement.”

With so many congressional and gubernatorial candidates locked in close races this year, Democrats can’t afford to show signs of complacency or sagging support. But Murrieta and others believe that only action — not promises of action — will help spur increased turnout among Hispanics with just five weeks until Election Day.

Appearing Thursday night at a gala hosted by the Congressional Hispanic Caucus Institute, Obama said he will use his executive authority to revamp the nation’s immigration policy sometime between Election Day and before the end of the year.

“If anybody wants to know where my heart is or whether I want to have this fight, let me put those questions to rest right now: I am not going to give up on this fight until it gets done,” he said.

Obama also urged Hispanic lawmakers and activists in the crowd to works to ensure a record Latino voter turnout this year.

“Sí se puede si votamos — yes we can if we vote,” he said in Spanish and English.

“What happened to change we can believe in?” a young heckler shouted at Obama as she was escorted from the hall.

Inside the room, Obama was speaking to some of the lawmakers most upset by his decision to wait.

“We would not wait until after November if it was an issue affecting the gay and lesbian community,” Rep. Luis V. Gutierrez (D-Ill.), a critic of Obama’s work on immigration, said at the conference Wednesday afternoon. “If this was about women’s reproductive rights, if this was about the minimum wage, if this was about a series of other issues, the Democratic Party would come together.”

Rep. Joaquin Castro (D-Tex.) said he’s found widespread frustration. “A lot of people understand there’s a political calculation, but those same people understand there’s a lot of people suffering because he didn't act,” he said in an interview.

Labor Secretary Tom Perez, who is under consideration to be Obama’s next attorney general, sought to reassure conference attendees Wednesday. But his message fell flat.

“The question of executive action, my friends, is a ‘when?’ question,” Perez said. Immigration, he added later, “is all about his values and his leadership. And that’s why I love working for this president.”

It’s the kind of line that might earn a response from a friendly crowd — but nobody in the room applauded.

Obama was already suffering from gradual disenchantment among Hispanics before he made his decision last month to delay action on immigration. In a Washington Post-ABC News poll last July, Obama had a 68 percent approval rating among Hispanics for his handling of immigration. By September, that number had dropped to 42 percent.

From 2012 to 2013, Obama went from 75 percent approval to 52 percent among Hispanics in national Gallup polls; he’s at 48 percent among Hispanics in the group’s most recent approval tracking this month.

Maria Teresa Kumar, president of Voto Latino, a nonpartisan group seeking to register young Hispanic voters, told conference attendees that despite any misgivings, Latinos need to turn out this year in record numbers to remind Obama, his party and Republicans that they want the immigration issue settled.

“Until we try to actually recognize that our number one initiative is to organize each other . . . we’re always going to be left behind,” she said. “And it gets to a point that it’s no longer anyone’s fault but our own.”

But far beyond Washington, activists are struggling to convince skeptics.

On a busy day, Murrieta and his team fan out to find would-be voters at grocery stores, elementary schools and bus stops in Denver and Pueblo, Colo. Murrieta said the typical number of sign-ups has plummeted from maybe a dozen a day before Obama’s decision to as few as three a day now.

“Less people are willing to talk about elections,” he said. “We’ve just had to get more creative and really find ways to talk about the issues and the elections.”

There’s similar resistance in Arizona, said Raquel Teran, who leads a team of 35 scouring the Phoenix and Tucson areas for new voters.

If Obama “would have acted before the election absolutely it would have been easier,” she said. “A lot of the Latino community are watching how the debate is advancing and there would be energy.”

Some activists are also encouraging Latinos to skip voting in a key contest: their U.S. Senate race.

Presente.org, a Los Angeles-based Latino rights group claiming 250,000 members nationwide, is encouraging followers in four states to skip voting to reelect Democratic Sens. Mark Pryor (Ark.), Mary Landrieu (La.), Jeanne Shaheen (N.H.) and Kay Hagan (N.C.). Those states have about 353,000 eligible Latino voters — a small number, but a potentially critical bloc of support in close races.

All four senators, along with Sen. Joe Manchin III (D-W. Va.), voted last month on what Republicans cast as an attempt to roll back Obama’s program giving temporary legal status to hundreds of thousands of children of illegal immigrants. They did so under pressure from their GOP opponents.

Presente — which specializes in using social media and text messaging to rally supporters — is using microtargeted Facebook ads to tell members in Arkansas, Louisiana, New Hampshire and North Carolina that the senators voted with Republicans “in an effort to derail President Obama’s executive action that would provide relief for immigrants.”

“By no means are we saying vote Republican, we’re simply saying that on that item on the ballot, skip it,” said Arturo Carmona, executive director of Presente. Instead of voting in the Senate race, “There are a lot of other important items on the ballot that they should pay attention to,” he said.

Representatives of the Democratic campaigns did not respond to requests for comment. Other activists suggested the boycott would have little, if any, impact.

“It’s not going to work. It’s being a little disingenuous and insulting,” said Ben Monterroso, executive director of Mi Familia Vota.

Castro said that if voters express any doubts about Obama or Democrats, he tells them: “The chances of passing comprehensive immigration reform if Republicans take over the Senate are even more slim than they are now.”

Katie Zezima and Peyton Craighill contributed to this report.