Two hundred and twenty-four years of white voter dominance of presidential elections officially ended with Mitt Romney's loss last month, and the GOP has such a bad brand among Hispanics that victory in 2016 and beyond will be a slog, according to a long-awaited Republican analysis.

"Republicans have run out of persuadable white voters," said the study from GOP polling group Resurgent Republic.

"Mitt Romney won a landslide among white voters, defeating Barack Obama by 59 to 39 percent. In the process he won every large segment of white voters, often by double-digit margins: white men, white women, white Catholics, white Protestants, white old people, white young people. Yet that was not enough to craft a national majority," they said.

"Trying to win a national election by gaining a larger and larger share of a smaller and smaller portion of the electorate is a losing political proposition," added the outfit that is the GOP answer to James Carville and Stan Greenberg's Democracy Corps.

The solution, said Resurgent, is winning non-white minorities, especially Hispanics and Asians. But in Resurgent's newest post-election survey, the GOP was shown to have a bad reputation in Latino communities. The evidence: Mitt Romney won just 27 percent, and even lost those who consider themselves conservatives. His was the worst Hispanic vote of any Republican candidate in a two-candidate election since Watergate. Third party candidate Ross Perot ran in 1992 and 1996 and his Texas roots pulled some votes away from former President George H.W. Bush.

"Republicans should not expect to win a majority of the Hispanic vote nationally any time in the foreseeable future. But they can reasonably win more than 40 percent of Hispanic voters in many states," said Resurgent, which said that was enough help former President George W. Bush win reelection.

Republicans have seized on their loss by talking up immigration reform, but Resurgent suggested that new legislation isn't a silver bullet, largely because Hispanics see the Democrats as more understanding of their situation.

"Republicans face some major challenges among Hispanic Americans, problems that will not be resolved just by passing immigration reform legislation. Years of harsh rhetoric and punitive policies will not be undone overnight. Fixing a broken immigration system is necessary but not sufficient to make Republicans competitive in the Hispanic community," said the influential polling group.