A number of immigration legal experts pointed out that a backlash against the president for acting on immigration is likely to come regardless of his timing, whether he acts now, or sometime between November and the end of the year, as he has now reportedly promised. Republicans in several highly contested races are already running campaigns that dwell on Obama's intention to act unilaterally on the issue of immigration.
"Make no mistake: President Obama plans to grant amnesty; it's just that he will cynically wait until after the election so as not to harm Senate Democrats like Jeanne Shaheen," New Hampshire senate candidate Scott Brown said in a statement. Brown now trails Democratic Senator Jeanne Shaheen by only two percentage points, after polls in July suggested a gap of more than 12 points.
"There's some sentiment that executive action on immigration reform might not actually affect the elections, because the GOP are using his intent as a talking point already," said Marielena Hincapié, the executive director of the National Immigration Law Center.
If Republicans manage to control both the House and the Senate come November—the odds are currently stacked, if ever so slightly, in their favor in the Senate—it could become even more difficult for lawmakers to push through sweeping legislative reform, or for the president to act unilaterally without even more serious political backlash.
For one, the GOP-controlled chambers might work to limit executive power. "A Republican-controlled Senate could mean they will actually try to push through legislation and bills to challenge the president's authority," Hincapié said, suggesting that GOP lawmakers could push for laws that make it more difficult for the president to enact sweeping reform without the support of the Senate or the House.
While that scenario is unlikely to unfold, the GOP could still tie the president's hands a bit, according to Hincapié. "They could, for instance, push to prove that funding simply isn't there for the reforms he announces," she said.
Republicans could also work to draft their own immigration reform proposal, which might tempt Obama to further postpone unilateral action. "If they win both the Senate and the House, it's very likely they will at least try to make an attempt at immigration reform," Hincapié said. "The concern is whether the White House will decide to delay any executive authority reforms in order to wait and see what the Senate and House do in terms of legislation."
Obama is unlikely to sign any legislation proposed by a Republican-controlled House and Senate. But Hincapié suggests that the longer the president waits, the weaker the reform is likely to be.
In any case, a Republican-led Senate means any action by the Obama administration will appear particularly rogue, considering that neither the House nor the Senate will likely endorse it (Republicans are far less likely to prioritize the expansion of pathways to citizenship).
"It could be Obamacare all over again," said Tamar Jacoby, president and CEO of ImmigrationWorks USA. "It won't even be about immigration—it will turn into a question of constitutionality."