"If the party doesn't change, we can put the party on a Carnival cruise line ship during the next election and they can enjoy themselves up and down the Caribbean because that's about the size it will become," says John Weaver, a GOP strategist who ran ex-Utah Gov. Jon Huntsman's presidential bid.
The numbers prove the point: Exit polls show President Barack Obama won overwhelmingly among black voters, Latinos and other minorities; ran up a big lead with young voters; and amassed a significant majority of women.
Mitt Romney, on the other hand, captured a majority of white voters, men and those 45 and older.
"Trying to increase the share of a shrinking, dying demographic old, white men is not a winning strategy," says Mark McKinnon, a former adviser to President George W. Bush and co-founder of the group No Labels that seeks to break the partisan gridlock.
"The GOP has to recognize that demographics is destiny in politics. Time to wake up and smell the coffee."
Moving forward • House Speaker John Boehner, who holds onto a Republican majority in the House, albeit a slightly slimmer one, has already signaled that the party needs to tackle immigration reform a crucial departure that could help it with a growing cross section of voters.
"It's an important issue that I think ought to be dealt with," Boehner told ABC News' Diane Sawyer last week after the election. "This issue has been around far too long, and while I believe it's important for us to secure our borders and to enforce our laws, I think a comprehensive approach is long overdue, and I'm confident that the president, myself, others can find the common ground to take care of this issue once and for all."
Weaver, the architect of Sen. John McCain's 2000 presidential bid, says Republicans should be first to put out a plan to fix immigration even if Obama ends up taking credit for it.
"We have to fix our Hispanic problem pronto," Weaver says, noting GOP participation could go a long way in attracting voters.
Beyond that, he notes, "We've got to make long-term concerted efforts into African-American, Asian, Hispanic, [lesbian, gay, bisexual and transgender] communities and not just give it lip service but understand their issues and promote policies that can be looked upon with favor by them. And you can do all those things while being conservative."
Ralph Reed, who led the Christian Coalition in the 1990s and continues as a voice in the conservative movement, said after the election that the GOP can win back many voter blocs without wholesale change.
"If the Republican Party wants to be competitive in national elections, it will have to nominate candidates who can appeal to young voters, women, Hispanics and other minorities," Reed said. "Otherwise, they will likely see more elections similar to the 2012 outcome. The good news for the GOP is many of those voters are conservative and are people of faith."
Former GOP Rep. Joe Scarborough, now a host of MSNBC's "Morning Joe," waxed on after Tuesday's votes poured in, saying that Republicans need to stop being afraid of the more right-wing extremists in tackling controversial issues. You don't go half-in on immigration reform, for example, and you don't pull back when some blogger or "extremist in talk radio attacks you."
"Because for every one extreme voter you lose, you pick up four solid Republicans in the middle," he said last week.
Principle vs. marketing • For others, the GOP's problem is not in its political stands but in its marketing. Party elders need to steer away from and immediately denounce comments from candidates that a child born from rape is a gift or that a woman's body prevents pregnancy from "legitimate rape."
Those kinds of comments, particularly insulting to women, came back to hurt the GOP overall, Republicans says, and distracted from a more positive message. That doesn't mean, according to this school of Republican thought, that the party needs to change its positions on abortion and gay rights.
After all, there were majorities of groups that Romney did win this cycle: white women, men, college graduates, middle- to upper-class families and those people who said they attended church once a week or more, according to exit polls by a consortium of news outlets.
It's not the brand that's the problem, insists Rep. Jason Chaffetz, R-Utah, but the way that brand is advertised.
"There are some core issues that we are going to have to have a discussion about," Chaffetz says, mentioning immigration, gay marriage and abortion. "We can be more eloquent in stating our position."
Chaffetz who notes his own family doesn't have a landline phone and watches little broadcast television says Democrats are doing a better job communicating with a new generation of voters, and the GOP needs to catch up.
"We are on the right side of the issues but our coolness quotient is not as good as it should be," he says. "The last month we criticized President Obama for going on 'The Tonight Show,' 'Letterman' and 'The Daily Show' … Rather than scoff at it, we ought to do it."
KellyAnne Conway, a Republican strategist and founder of Washington-based The Polling Company, dismissed the idea that the GOP must change its principles.
"The party doesn't need to moderate, it needs to modernize," Conway says. "It needs to understand the changing cultural, demographic differences in the nation."
Democrats have proven their ability to reach out to voters through specific marketing finding black voters in salons or barbershops, mothers in gyms or playgrounds, Conway notes. The problem this election wasn't that Romney touted the conservative talking points, but that he didn't connect to the voters he needed.
"Anybody who thinks Mitt Romney lost the election because he was too out in front on traditional marriage and life, please send me those clips," Conway says. "Where was that in the teleprompter?"
Matt Canham contributed to this story.
View the entire Election Day polls result: