Nearly a year ago, President Obama announced a sweeping plan to shield millions of illegal immigrants from deportation, arguing that a mass exodus of undocumented migrants  “would be both impossible and contrary to our character.”

Since then, Obama’s executive actions have resounded on the presidential campaign trail, with most Republican candidates vowing to overturn them and Democrat Hillary Rodham Clinton strongly supporting them. Activists nationwide have mobilized to help immigrants apply for relief.

Yet Obama’s plan has gone — and may be going — nowhere. That’s because it remains in legal limbo, sitting in a New Orleans federal appeals court that heard arguments in July but has yet to issue a decision.

The three-month wait doesn’t sit well with immigrant advocates, who last week launched a nine-day fast and vigil outside the federal courthouse, where three judges from the U.S. Court of Appeals for the 5th Circuit are debating the program’s fate.

“Three months is too long. There are five million lives in limbo,” said Tara Raghuveer, policy and advocacy director for the Chicago-based National Partnership for New Americans, a coalition of 37 immigrant advocacy groups. She voiced concern that the 5th Circuit, known as one of the nation’s most conservative appellate courts, may be joining opponents of the program in “an intentional legal strategy to delay any potential implementation.”

Erin F. Delaney, an associate professor of law and political science at Northwestern University, said the delay is not unusual, given the complicated legal issues at stake. “I understand why everyone is upset,” said Delaney, a former U.S. Supreme Court clerk. “But three months, over the summer, with a case of this complexity, doesn’t seem out of the norm at all.”

The political stakes are also high. Over vehement opposition from Republicans, Obama announced in November that up to 5 million illegal immigrants would be eligible to be shielded from deportation — including undocumented parents of U.S. citizens and legal permanent residents — as long as they met certain criteria. One of the signature initiatives of his presidency, the plan also expands a 2012 program that has deferred the deportations of hundreds of thousands of immigrants brought to the United States illegally as children and has granted most of them work permits.

But after Texas and 25 other states sued the administration, calling the moves unconstitutional, a federal judge in Texas in February put them on hold until the case is resolved. The 5th Circuit in May upheld that injunction, then held oral arguments in July on the substance of the case, with hundreds of immigration advocates rallying outside. The 2012 program remains unaffected.

Legal experts have long said that the court battle could last late into Obama’s term, especially if it winds up at the Supreme Court. And the window for the high court to hear the case during its current term is starting to close: the court generally must accept a case by January to hold oral arguments and reach a decision before it adjourns in June.

A case accepted after January would like be held over for the term that begins in October 2016, pushing the highly charged issue into the next administration.

Amid the heightening interest, it remains unclear when the 5th Circuit judges will weigh in. “Whenever the judges rule on it, they rule on it,” Tom Plunkett, the court’s chief deputy  clerk, said late Friday.

Plunkett said the court does not track how long cases normally take and where the immigration matter stacks up. “Some cases take longer than others,” he said. “Obviously, it’s a very complex issue at stake.”

Robert Barnes contributed to this post.