On immigration, will Obama shape his legacy or the next election?

President Obama and his team spent hours last week deliberating over how and when to fulfill his promise to use his executive power to change the immigration system. They pored over legal precedent and policy data and debated political fallout.

But none of their analysis could answer the question that his decision may turn on: Does the president want to shape his legacy, or the next election?

With immigration, Obama has landed on an issue that carries both risk and reward — according to some Democrats, it carries reward for him and immoderate risk for them. It’s a place familiar to second-term presidents, who often look for bold, history-making moves as they eye the end of their time in office while their allies in Congress look squarely at the next election.

In this case, several Democrats in tight races have expressed opposition to Obama’s unilateral action plan, amid worries that such a move will fire up the GOP base and turn off more conservative Democrats just weeks ahead of the midterm election. Some strategists have urged him to at least delay the most sweeping changes to immigration policy, including a proposal that could potentially shield millions from deportation, until after the election.

The White House has acknowledged this tension as “cross pressures” in the debate. Aides say the president has not made his decision and argue that Obama is deeply focused on the legal grounding of his choice, rather than the political dynamics.

Still, the president is considering proposals that would please endangered Democrats but disappoint advocates and Latino voters. One that the administration looked at would roll out a series of enforcement measures first and push back the deferred deportation plan until later in the year, according to a White House official.

Obama, who once voiced doubt about whether he had legal authority for the sort of moves he’s considering, has appeared torn over the choice. Although he repeatedly promised to act immediately after he received a set of recommendations, which he said would happen “by the end of summer,” the president said Thursday that the timeline may slip.

Still, he affirmed he would act.

“Have no doubt: In the absence of congressional action, I’m going to do what I can to make sure the system works better,” Obama said Thursday.

Several White House officials and allies say there’s little doubt what the president wants to do. Frustrated by congressional deadlock, Obama has spoken passionately about providing relief to immigrants who have deep roots in the U.S. but are living in the shadows of a broken system. He wants to bring as many out into the open as the law will allow, officials said.

These officials are optimistic about how a major executive action might influence history’s evaluation of Obama’s presidency. Those close to the president see it as a program that, along with the healthcare law and expansion of equal rights for gays and lesbians, could cement a legacy on a par with the achievements of the civil rights era.

“He sees immigration as an issue that speaks to a larger theme of his candidacy and presidency — that our diversity as a nation is strength, not a weakness, and is part of America’s genius,” said Jon Favreau, the president’s former longtime speechwriter.

An immigration program would solidify Obama’s place alongside Presidents Reagan and Lyndon Johnson as a leader who reshaped the government’s role in American life for a generation, one top White House official said. The advisor declared it would place Obama as the progressive version of Reagan.

These ambitions are slamming up against political and legal realities.

Unlike Reagan and Johnson, Obama has not found a way to win over opposition in Congress and is left searching out the limits of his executive authority to accomplish his aims. His decision to use his executive power to fill in for stalled legislation will undoubtedly provoke lawsuits and complaints of overreach from his political opponents. It may only ding his already damaged public approval rating, but it is unlikely to help Democrats running in tough races in Arkansas, Louisiana and Alaska.

Sen. Michael Bennet, the Colorado Democrat who favors executive action but, as chairman of the party’s campaign committee, also understands the worries of Democrats running in red states, has conveyed those concerns to the White House, according to people familiar with the conversations.

Several races that could determine whether the president’s party will continue to control the Senate next year will probably be decided by thin margins. In those races, the focus on immigration could be an unwelcome distraction for Democrats and an easy target for Republican critics of executive overreach. In North Carolina, Sen. Kay Hagan, who is among the most endangered Democratic incumbents, thinks “Congress needs to handle this issue and she doesn’t think the president should do this at all at any time,” her campaign spokeswoman said.

Such concerns have some speculating that Obama will take a middle route. The president, whose aides once declared his foreign policy motto was “don’t do stupid stuff,” isn’t known to be a risk taker.

On immigration, in particular, he has been cautious. He broke a promise to back a bill in his first year in office, and, amid concerns about his party’s chances in the 2010 midterm election, let the issue fall behind other priorities. He waited a year and half after legislation died in Congress before taking major executive action in 2012 to create a program for so-called Dreamers, immigrants who arrived in the U.S. illegally as children.

That action was rewarded with broad support among Latino voters in Obama’s reelection. Still, there is wariness that the president may not be committed to the next step he promised. As comprehensive immigration legislation stalled in Congress this spring, Obama avoided acting, in hopes that Republicans would compromise. When advocates seized on statistics showing 2 million instances of people being sent out of the U.S. under his tenure — labeling him “deporter in chief” — an irked Obama declared he was obliged to enforce the laws.

“I cannot ignore those laws any more than I can ignore any other laws on the books,” he said in March.

But by June, with the bipartisan legislation all but dead in the House, Obama began to emphasize his option to take executive action. He has raised expectations so high, advocates noted, that delaying the decision until after the election would not be received well.

“They have to be very careful of how they’ll be perceived as pulling back and breaking his promise,” said Angela Maria Kelley, an immigration expert at the Center for American Progress. Skeptics worry the president will follow through with the enforcement changes, but back out on the deferred deportation plan. The president will have to undertake a “high level of persuasion” to convince the advocates and Latino community of his intentions, Kelley said.

Obama will also have to reckon with the ramifications for immigrants awaiting his choice, said Rep. Luis Gutierrez (D-Ill.), a leading advocate for action in Congress. A two-month delay could result in thousands of deportations that might not have happened were the program enacted earlier, he said.

“It isn’t as if this has no impact,” he said.

This moment leaves Obama with a clear choice, said Cristina Jimenez, a co-founder of United We Dream, an organization of young immigrants. Does he want to be the president thwarted by a deadlocked Congress on an issue important to coming generations of Americans? Or, she asked, “Do you want to be the president that is remembered by Latinos as the deporter in chief?”

Lisa Mascaro in the Washington bureau contributed to this report.