They hoped that Obama, bolstered by the 70 percent-plus support he received from Hispanic voters, might now feel ready to champion the cause he largely avoided during his first term.
And they thought that Republicans, after the thumping they got at the hands of Latinos in the Nov. 6 election, might soften their resistance in order to stay competitive in future elections.
But as advocates mobilize for what is likely to be a two-year drive to get an immigration law enacted, their optimism may be tested by a dose of reality.
However sympathetic Obama might be, he will be preoccupied with fiscal battles well into next year and less likely to engage in the kind of salesmanship analysts believe is essential to sell broad immigration policy changes to the public.
And Republicans in Congress, as a group, may not be eager to reverse long-held and deeply felt positions on immigration in an era when so many are vulnerable to primary election challenges from the right. Plus, they may be just as consumed by fiscal issues as the rest of Washington.
Democratic Senator Mark Warner noted the fiscal cliff - the tax increases and spending cuts set to take effect in January - will suck up Washington's energy early in 2013, even as his party wants to use the new Congress to tackle big issues like immigration, climate change and job creation.
"We're not going to get to any of that until we get this (fiscal cliff) fixed, until we lance this boil," Warner said in a meeting with Reuters reporters and editors last week.
Immigration reform, which has failed repeatedly in Congress over the past decade, aims to accomplish several goals - none of them easy.
For Democrats and their labor union supporters, the 11 million undocumented foreigners, many having spent years in the United States, should be allowed to come out of the shadows and given a path to citizenship while working here legally.
Many Republicans complain that this approach would reward those who broke the law by jumping in front of those waiting to emigrate legally.
The 11 million includes the children of illegals who have been brought into the United States through no fault of their own. Obama, impatient with Congress' inaction and with an eye on re-election, last June moved on his own to allow some of them to avoid deportation for two years and obtain work permits. .
For Republicans, stronger enforcement measures are necessary to keep more illegals from entering the United States through states bordering Mexico, especially if an improving U.S. economy begins creating more jobs. Democrats argue that tough controls already are in place.
Both sides want to more efficiently verify legal workers in the United States, while the business community wants better access to low-paid farm workers and well-paid high-tech workers on a temporary basis, which troubles some union leaders.
Supporters of reform hope to see progress soon.
"At a minimum, they'll want to have a bill (introduced) by early spring, around April," said Andrea Zuniga DiBitetto, who follows Congress for the AFL-CIO, the confederation of U.S. labor unions.
Senator Dick Durbin, the No. 2 Democrat and a close ally of Obama, told Reuters he aims to get such a bill onto the Senate floor for votes next year. Senate Judiciary Committee Chairman Patrick Leahy, in an interview, said his panel would move early to write the measure.
REPUBLICANS WEIGH RESPONSE
It was Obama's re-election that emboldened his fellow Democrats in Congress to move swiftly with comprehensive immigration legislation next year.
It also led some Republicans to conclude that they have to start responding to the concerns of the fastest-growing demographic group in the United States.
Republicans' Nov. 6 election losses prompted House of Representatives Speaker John Boehner to note the need for immigration reform.
But one senior House Republican aide, who did not want to be named, noted that House Republicans as a whole are "still pretty conservative."
He added that immigration "won't be the first thing we do or even the second, but we have two years to act" before the 113th Congress ends.
And Boehner, however open he may be, does not control the Republicans he leads in the House.
The next chairman of the House Judiciary Committee, the panel that would craft that chamber's immigration bill, could be Representative Bob Goodlatte, a conservative who opposes amnesty for those who came to the United States illegally.
Goodlatte also has praised the controversial Arizona law cracking down on illegal immigrants, which has been partially struck down by the U.S. Supreme Court.
Representative Steve King, also a conservative Republican, said during a post-election press conference that Obama could not be trusted to enforce any immigration reform law that Congress might produce.
And he downplayed any notion that an alienated Hispanic community contributed to Republican losses in this year's elections.
But Representative Raul Labrador, a fellow conservative and a native of Puerto Rico, quickly rebutted King, arguing that Hispanic votes are essential to a healthy Republican Party.
"One of the biggest things conservatives talk about often is that we want to fix a broken government. Well, if you know anything about immigration law, the immigration system is absolutely broken in the United States," said Labrador, adding that he is eager to tackle reform.
In the Senate, the work will start without some of the titans of earlier immigration battles. Edward Kennedy, a Democrat, died in 2009. Arlen Specter, a moderate Republican-turned-Democrat, was defeated in a 2010 Democratic primary election and left the Senate before his death last month.
Senator Richard Lugar, a moderate Republican, will leave at year's end along with Joseph Lieberman, an independent. It is unclear whether John McCain, the Arizona Republican who ran for president in 2008, will help lead the fight or sit on the sidelines.
Senate Majority Leader Harry Reid and Durbin, joined by fellow Democrats Robert Menendez and Charles Schumer, will watch closely to see whether some fresh Republican faces become serious players.
Among those Republicans are first-term Senator Marco Rubio of Florida and incoming Senators Jeff Flake of Arizona and Ted Cruz of Texas - all conservatives from states with large Hispanic populations.
In his first term, Obama disappointed many Hispanics and Democrats with his aggressive deportation policy and failure to seek broad immigration reforms, opting for a policy decision that defers deportation for some younger illegal immigrants who are enrolled in school.
A House Democratic aide, who asked not to be identified, complained that Obama, when it came to immigration reform, "for the most part sat back and told Congress to work it out and 'I'll give a speech.' He's going to have to be more hands-on" this time around.
Meanwhile, Hispanics are hoping that the 2012 election has finally opened the door to change.
"We have a check to cash, and 2013 is going to be a new year," said Daniel Rodriguez, an Arizona activist with United We Dream, a network of youth-led immigration groups. (Additional reporting by Thomas Ferraro and Doug Palmer; Editing by Fred Barbash and Xavier Briand)