In the wake of the 2008 election, conservative Republican strategists like Karl Rove, Grover Norquist and William Kristol warned that their party faced even worse defeats if it continued in its anti-immigrant posturing.

“An anti-Hispanic attitude is suicidal,” Rove wrote. The decision to “demagogue” the immigration issue was a “totally self-inflicted wound by House Republicans,” Kristol declared. “Beating up on immigrants,” Grover Norquist said, “loses you votes.”

Their advice was rejected. Republicans running for the House and the Senate defiantly calculated that they could win in 2010 with a surge of white voters, affirming the Republican role as the default party of white America. Initially, this approach appeared quixotic. A demographic tidal wave of African-American and Hispanic voters threatened to wash the Republicans out to sea.

But many Republican candidates — incumbents and challengers — did not budge. They not only held firm in their adamant opposition to immigration reform (despite its crucial importance to many Hispanic voters), but they also became even more hard-nosed. Former apostates on the issue, like Senator John McCain of Arizona, who had proudly backed immigration reform in 2004 and 2005, saw the light — in other words, read poll data on Republican voters — and moved to the right.

To use just one particularly egregious example, Senator David Vitter — who admitted that he had “let down and disappointed” family, friends and supporters but refused to answer questions about his connections to prostitutes — used an outspoken anti-immigration ad to win re-election easily in Louisiana.

The decision to carry the banner for conservative white America paid off in the midterm elections — helped enormously, of course, by a dismal economy under a Democratic president and a Democratic Congress, as well as conservative hostility to the administration’s health care program and economic stimulus legislation.

In 2010, the Republican white strategy was boosted by the fact that minority turnout traditionally drops in non-presidential years, perhaps especially so without Obama on the ballot. But the scope of success went far beyond expectations.

The percentage of non-Hispanic whites voting for Republican House candidates in 2010, 62 percent, set a record for off-year contests, beating even the 1994 Republican rout when Republicans got 58 percent of the white vote. In presidential elections, you have to go back to the landslide Republican victories of 1972 (Richard Nixon versus George McGovern) and 1984 (Ronald Reagan versus Walter Mondale) to get white Republican margins similar to those of 2010. McGovern and Mondale carried just one state each, Massachusetts and Minnesota respectively.

Another way of looking at it is this: fully 88.8 percent of all ballots cast in 2010 for House Republicans were cast by whites, compared to 63.9 percent for Democrats.

The degree to which the Republican Party has become a white party is also reflected in the composition of primary voters. For example, on March 4, 2008, in Ohio — where non-Hispanic whites are 81.1 percent of the population, blacks 12.2 percent, and Hispanics 3.1 percent — the Republican primary turnout was 97 percent white. Hispanics were 2 percent and the black turnout was so low it was zero percent, statistically speaking. One percent was described as “other.”

In the Jan. 19, 2008, South Carolina primary, 96 percent of the Republican turnout was white, 2 percent black, 1 percent Latino and 1 percent other. The population of the state is 64.1 percent white, 27.9 percent black and 5.1 percent Hispanic.

Now, moving toward what has all the markings of a historic ideological and demographic collision on Nov. 6, 2012, Republicans are doubling down on this racially fraught strategy.

While the subject of race and of the overwhelmingly white Republican primary electorate are never explicitly discussed by Republican candidates, the issue is subsumed in blatant anti-immigration rhetoric. As Rick Perry, the governor of Texas, learned the hard way, voicing sympathy for the plight of the undocumented is a sure way to lose ground.

The once-ascendant Perry torpedoed his own bid during a Sept. 22 debate in Orlando, Fla., when he endorsed using taxpayer dollars to educate the children of illegal immigrants. A single sentence started him on a downward slide:

If you say that we should not educate children who have come into our state for no other reason than they’ve been brought there by no fault of their own, I don’t think you have a heart.

The major threat to the Republican “white” strategy is a revival of the high turnout among minorities that carried Democrats to victory in 2008. Republicans, however, are taking advantage of their newly won control of state governments across the country to enact laws designed to suppress minority turnout.

Republican legislators and governors are reversing decades of liberalized access to the ballot by passing laws restricting or eliminating election day registration, early voting, the broader use of absentee ballots and voting by mail.

At least eight states have enacted legislation to curb access to the polls, including three key battlegrounds in the presidential race: Wisconsin, Florida and Ohio.

Liberal groups, including the Brennan Center for Justice at the New York University Law School, estimate that as many as five million men and women will be unable to vote because of these laws, which disproportionately affect minority voters.

With less than a year to go until the election, poll data suggest that the Republican “white” strategy has a chance of working. Since 2008, the Republican Party’s biggest gains, and Obama’s sharpest declines, have been among white voters.

Gene Ulm, a partner at Public Opinion Strategies, a Republican firm that conducts the NBC/Wall Street Journal surveys with Peter D. Hart Research Associates, a Democratic company, wrote on September 16 that among whites on two key measures — ratings of Obama’s job performance and his image or personal favorability ratings — the president has dropped below a crucial tipping point: “Even following the disastrous-for-Democrats 2010 mid-term elections, President Obama’s image was net-positive among white voters, 45%-38%; it is now upside-down by a wide margin, 36%-52%.”

The non-partisan Pew Research Center reported in July that measurements of partisan identification showed increasing Republican margins among white voters. In 2008, 46 percent of whites said they were Republicans or generally voted for Republicans, and 44 percent were Democrats, a virtual tie. By the summer of 2011, however, the Republican advantage had grown to 52-39.

The shift, Pew noted, was “particularly pronounced among the young and poor.” Whites under 30 in 2008 favored Democrats by seven points, but by mid-2011 gave the Republican party an 11 point edge, a substantial 18 point shift. Similarly, whites with incomes under $30,000 had favored Democrats by 15 points in 2008, but in 2011 tilted Republican by four points, a 19 point shift.

Regardless of the ultimate success of the Republican strategy, these trends guarantee that race and ethnicity will be dominant themes underlying the 2012 election, infusing the debate over deficits, taxes and government spending. In the 140 years from the end of Reconstruction to the present, no matter what the motives of those engaging in the debate, these divisive issues have worked to the advantage of economic elites and there is no reason to believe this will change.

Thomas B. Edsall, a professor of journalism at Columbia University, is the author of the forthcoming book “The Age of Austerity: How Scarcity Will Remake American Politics.”