President Obama's recent overhaul of his deportation rules has electrified the largely partisan debate over immigration policy heading into the next Congress.
The politics surrounding the unilateral action could reverberate for years to come, as both conservatives and liberals have taken the move as a call to action that could affect congressional races in 2016 and beyond.
"We have a responsibility to start moving serious legislation ourselves," Rep. Tom Cole (R-Okla.) told The Hill this month.
On the left, Democrats are equally invigorated, viewing the White House action as evidence that Obama is ready to use the final two years of his presidency to push promised reforms.
Many Democrats were up in arms that Obama decided to delay his deportation order until after the elections — a delay they say alienated Hispanic voters and contributed to Democratic losses in several swing districts.
In the wake of the executive action — which will halt deportations and make work permits available for as many as 5 million people living in the country illegally — the Democrats like their chances of taking back those seats amid a fight for the White House when many more voters, Hispanic and otherwise, are expected to participate.
"The turnout is going to be huge," one Democratic aide predicted Tuesday.
In a number of Senate and state-house races, Republicans made gains among Latino voters this year. But in House races, Hispanics sided 62 percent with the Democrats versus 36 percent who voted Republican — roughly the same split that governed the 2010 midterms, according to the Pew Research Center.
Heading into 2016, much will depend on the Republicans' legislative response to Obama's deportation policies.
GOP leaders in both chambers face heavy pressure from conservatives in and out of Congress to undo the more lenient rules and focus on tougher enforcement efforts targeting anyone in the country illegally.
But embracing a hard line could also scare off the growing Hispanic vote — currently representing 11 percent of the electorate — and shift that support back to 2012 levels, when Obama won over 71 percent of Hispanics.
"The question is: How are Republicans going to conduct themselves between now and then?" said the Democratic aide. "Are they going to realize that opposing immigration reform is not a winning strategy?"
Here are several tough-fought districts where Obama's deportation policies could play an outsized role in 2016.
• Florida-26: Republican Carlos Curbelo defeated freshman Rep. Joe GarciaJoe GarciaFreshman Curbelo wins reelection in Fla. LGBT Republican groups campaigning for Curbelo in Fla. House Democrats amplify anti-Trump strategy MORE (D) last month in this south Florida district, where more than 62 percent of eligible voters are Hispanic — among the highest percentages in the country.
Both contenders ran in strong support of comprehensive immigration reform, with Curbelo flipping national politics on its head by blaming Obama for not fighting hard enough to get it done. Garcia, for his part, minced no words in condemning Obama's delay on executive action.
A wildcard here could be Obama's new Cuba policies, as more than half of the Hispanic population is of Cuban descent. But Obama won the district with 53 percent of the vote in 2012. And with the new deportation policies in effect, Democrats are hoping 2016 will shift the seat back to their side.
• Arizona-2: In the closest race of the 2014 cycle, Republican Martha McSally defeated freshman Rep. Ron BarberRon BarberGiffords to lawmakers avoiding town halls: 'Have some courage' Ten House seats Dems hope Trump will tilt House conducts moment of silence for Tucson shooting anniversary MORE (D) in the drawn out fight for this border district in southeastern Arizona, where roughly one-in-five eligible voters is Hispanic.
McSally ran on a platform that emphasized border security and was a fervent critic of the Senate-passed immigration package, which she characterized as the "ObamaCare of immigration reform." She has also criticized the Dream Act and defended a controversial state law that empowered local law enforcers to check the immigration status of those they stop or arrest.
McSally's razor-thin margin of victory — she won by just 179 votes — has fueled Democratic hopes that they can retake the seat in 2016. But Obama's pre-election vow to act unilaterally on deportations put Barber in a tough spot in a state known for its strict approach to immigration enforcement. The next Democratic candidate could face similar hurdles now that the policy is in effect.
• Nevada-4: Freshman Rep. Steven Horsford (D) suffered a surprise loss to GOP challenger Cresent Hardy for control of this expansive central-Nevada district where more than 16 percent of eligible voters are Hispanic.
Hardy embraced eventual citizenship benefits for illegal immigrants brought to the country as children, and was open to providing a pathway to legalization for the older population, though "not necessarily to citizenship." Hardy has also rejected Obama's comprehensive approach to immigration reform, backing a piecemeal approach.
Obama won the district in 2012 with 55 percent of the vote, and Horsford hasn't ruled out a rematch in 2016.
• California-26: Freshman Democratic Rep. Julia BrownleyJulia BrownleyDems react to Flynn's request for immunity: 'Where there's smoke, there's fire' Lawmakers press Mattis on Marines nude photo scandal A guide to the committees: House MORE won a second term last month in a squeaker that was decided by less than 2,400 votes.
Brownley's challenger, Republican Jeff Gorell, was both a vocal supporter of comprehensive immigration reform and an unapologetic critic of the GOP’s resistance to a pathway to citizenship for those in the country illegally. "Republicans," he said after the election, "must make a policy paradigm shift that is consistent with the bold origins and values of our party."
The large Hispanic population in this coastal district — almost 31 percent of eligible voters are Hispanic — ensures that the Republicans will likely need to field a candidate with similarly centrist immigration views if they hope to unseat Brownley in 2016.
• Colorado-6: Rep. Mike Coffman (R) won a fourth term last month with 52 percent of the vote in this eastern suburb of Denver, where more than 12 percent of eligible voters are Hispanic.
Coffman has opposed citizenship benefits for adults and pushed hard for tougher border-security measures. But he also favors legalization steps, took great strides to reach out to Latino voters, including a recent effort to learn the Spanish language, and voted this month against a GOP proposal to undo Obama's executive action. His opponent, Democrat Andrew Romanoff, provided Coffman some cover on the thorny issue because of past positions deemed unfriendly to immigrants, including the repeal of mandated multi-lingual ballots.
Redistricting in 2011 made this formerly conservative district much more competitive, and Obama won it in 2012 with almost 53 percent of the vote.
• Texas-23: Freshman Rep. Pete GallegoPete P. GallegoVulnerable Texas GOP lawmaker survives rematch 5 races for tech to watch Vulnerable House freshmen passed most bills in decades, analysis finds MORE (D) lost his reelection bid last month to GOP challenger Will Hurd in this huge district in West Texas that borders Mexico for roughly 800 miles.
Hurd, a former CIA agent, bucked the conventional wisdom by taking a relatively hard line on immigration in a district where 61 percent of eligible voters are Hispanic, a vast majority of Mexican descent. He supports certain legalization benefits but opposes a pathway to citizenship for illegal immigrants.
Obama lost the district in 2012 by a margin of 48 to 51. But Hurd's victory was slight (2.1 percent), and Democrats are hoping the president's executive action will help flip the seat back to their side two years from now.
• Arizona-1: Democratic Rep. Ann KirkpatrickAnn KirkpatrickWomen make little gains in new Congress McCain wins sixth Senate term In Arizona, history and voter registration data gives GOP edge MORE won a third term in the tough-fought contest for control of this northeastern Arizona district. But, like that of Barber, her campaign was complicated by Obama's promise of executive action.
"Arizona has suffered from federal inaction to fix our broken immigration system," Kirkpatrick said on the trail. "But executive action can't fix it."
Kirkpatrick's GOP challenger, Andy Tobin, took an even tougher line on immigration reform. Tobin blamed Obama's deferred action for the migrant crisis and called for the National Guard to line the border. He also raised concerns that the migrants might bring Ebola into the country, and he ran campaign ads warning that Kirkpatrick's positions on border security make it easier for Islamic State terrorists to cross into Arizona.
Mitt Romney took this district with 50 percent of the vote in 2012, but Tobin didn't fare as well: Kirkpatrick won by 5 percentage points in a district where roughly 16 percent of eligible voters are Hispanic.