It's no longer news to anyone that Californians are mixing across ethnic and racial lines like never before. Over the past generation, the social barriers to intermarriage have steadily eroded. Indeed, it has become commonplace for analysts and commentators to point to the state's racially and ethnically-mixed future. Within a few generations, so goes the refrain, the average Californian will be an ethnic amalgam with equal parts Asian, Latino, black and Anglo ancestries. Not only have we fashioned a politically correct, culturally neutral image of California's mixed future, but we have studiously ignored the role of Latin Catholic culture in all this mixing.

While we may have accepted mixture as a fact of life, Californians are still not at all clear what it means. Two years ago, businessman Ward Connerly sponsored an ill-fated ballot measure that sought to prohibit the state from collecting racial data except for medical and law enforcement purposes. He contended that the rising frequency of intermarriage had made the concept of race irrelevant.

More recently, the Board of Regents of the University of California rejected another Connerly proposal that would have added a "multiracial" box on student application forms. While Connerly argued that the proposed category would give students another option in defining themselves, critics complained that it would make it harder to identify and collect data on minorities. Furthermore, the university must comply with federal government guidelines that insist on boiling all Americans down to five categories -- four racial and one ethnic.

So intent is the federal government on maintaining the legitimacy of the current racial system that the U.S. Census Bureau has proposed eliminating the "some other race" category from the 2010 decennial questionnaire. Largely driven by the increase in the Latino population, the 2000 census revealed that "some other race" had become the third-largest racial category in the nation. Ninety-seven percent of those who chose "other" as their race were Hispanic. It seems that Latinos are wreaking havoc on America's understanding of race. Indeed, nationwide, 42 percent of Latinos refused to categorize themselves as belonging to one of the four standard racial categories. In California, that percentage was as high as one in two.

If approved by Congress, the elimination of the "some other race" category would force a large percentage of Latinos, two-thirds of whom are of Mexican origin, to choose a racial label they evidently do not feel applies to them. The controversy is only the latest skirmish in the age-old battle between two racial systems: the Anglo Protestant and the Latin Catholic. Nowhere will the collision of these systems be more intense than in California.

In American history, the first battle between these two perspectives on race occurred in New Orleans after the Louisiana Purchase. Under French and Spanish rule, Louisiana had a three-part racial system consisting of whites, blacks and free people of color, who were racially mixed. But as Anglo Americans gradually solidified their legal and cultural control of the region, the system was pared down into two categories. Indeed, by 1892 Homer Plessy, who was seventh-eighths white, was arrested for sitting in a railroad car reserved for whites. Imposing a binary racial system required the obliteration of any in-between racial category, the denial of racial mixture, and the assertion of the primacy of racial purity. The legal battle over Plessy's arrest eventually reached the U.S. Supreme Court where, in an 1896 ruling in the seminal Plessy v. Ferguson, the court established the doctrine of "separate but equal."

A similar process occurred after the American conquest and annexation of the Southwest. Under Spanish and Mexican rule, racial categories were relatively fluid. While frontier Mexicans were not oblivious to race and tended to favor lighter-skinned individuals, skin color alone was not a major obstacle to social advancement. Mexicans tended to define people by culture and class in addition to race. While Anglo Americans viewed "black" or "Indian" as purely biological -- and as such inflexible -- classifications, Mexicans understood them as cultural categories as well. An Indian was not simply someone with Indian blood, but he was also an individual who behaved, dressed and spoke "like an Indian." A mid-19th century American visitor to the Southwest commented that while nomadic Indians hostile to Mexican settlements were considered "indios" by the Mexicans, those assimilated natives who spoke Spanish and lived largely according to Hispanic custom were considered Mexicans.

Like the French, the Spanish and the Mexicans also acknowledged racially-mixed, in-between identities. Furthermore, it was not uncommon for a racially mixed individual to change his racial classifications over time. Indeed, a host of the original settlers of Los Angeles changed their race between 1781 and 1790. For example, though identified as a mulatto in 1781, Manuel Camero had become a mestizo by the next census in 1790.

But once in charge, Anglo Americans imposed a more rigid racial order on the region. The first anti-miscegenation laws in the Southwest were passed not long after the Americans established control. Although Mexican Americans were generally not affected by this type of legislation, since under the treaty that ended the Mexican American War they were entitled to legally claim whiteness, they were nonetheless sensitive to the prejudice that inspired it. Whereas Texas and Arizona early on passed anti-miscegenation laws, New Mexico, with its large number of Mexican Americans in the territorial Legislature, refused to approve a similar measure. By the end of the 19th century, as Anglo migrants poured into the Southwest, racial lines had become less pliable and Anglo-Mexican intermarriage, which had been common in the years before and after the American takeover, became a rare occurrence.

In the South, the absence of black blood was the primary determinant of whiteness. But in the Southwest, whiteness -- indeed Americaness -- was more often defined in opposition to Mexicans. Whereas segregation against blacks was institutionalized, the segregation of Mexicans was generally extended unevenly and informally. Either way, it was understood that in the new order race was neither malleable nor subject to mixing.

The distinction between the Anglo and Latin approaches to racial difference stems from two competing theological strains of the Christian faith. Protestantism had emerged in Northern Europe contemporaneously with the spread of the printing press and the availability of books. Whereas for centuries, Latin Catholics had studied the Bible by looking at the magnificent stained glass windows of their cathedrals, Protestants were encouraged to make direct access to biblical texts. In other words, while Catholics internalized their beliefs through the use of symbol and ritual, Protestants stuck closely to the written word. Indeed, 16th-century Protestant reformers protested the prevalence of pagan superstition among the Christians of Europe and urged a more biblically-based or literal interpretation of God's will. Through the centuries, Catholicism had borrowed and absorbed a huge number of rituals and symbols from the very peoples they had converted. The more literal-minded Protestants sought to eliminate the open-ended ambiguity of folk Catholicism. The difficulty was that symbols are, by definition, open-ended. By contrast, printed texts lend themselves to more exacting and precisely defined interpretations.

The two Christian faiths' missionary efforts among the Indians of the Americas illustrate the fundamental difference in their attitude toward the "other." While Protestant missionaries tended to be rigid and uncompromising in their approach to indigenous religious, Catholics had learned to accept and sometimes encourage cultural and spiritual syncretism. Whereas Protestant missionaries were determined to preserve the doctrinal and cultural purity of their faith, Catholics willingly experimented with the fusion of disparate belief systems.

The Anglo-Protestant emphasis on theological purity and the Latin-Catholic willingness to accept blending presaged the differences between their respective approaches to race and racial mixture. The Anglo-American conception lent itself to the emergence of a pluralistic society, in which groups would and should remain distinct, while the Latin-Catholic world view encouraged the practice of racial, cultural and religious mixture, providing that the Latin-Catholic heritage remained the pre-eminent ingredient.

One cannot properly understand the increase in crossethnic marriage in California without acknowledging the Latinization of the state. While racial attitudes have become more liberal over the past generation, they alone don't account for the market increase in intermarriage. Today, two-thirds of multiracial and multiethnic births in California involve a Latino parent. The 1948 court case, Perez v. Sharp, that led to the end of anti-miscegenation laws in California was filed by a Mexican-American woman married to an African-American man. In other words, the rise of intermarriage in California is not occurring in a neutral field, but in an increasingly Hispanic Catholic context.

This does not mean that racism or the concept of race will disappear. But race will be seen as a more fluid category, similar to how we view ethnicity today. In other words, race will increasingly be understood as a cultural as well as a biological classification. The Latinization of California has facilitated the re-emergence of the Latin- Catholic view of race, but it is not likely to obliterate the Anglo-Protestant perspective. Indeed, the tension between the two world views is likely to stay with us for some time to come. For the foreseeable future, Californians will have to balance the dual notions of synthesis and separation, mixture and pluralism. In the meantime, the state and federal government should think twice about obliging all Latinos to conform to Anglo-American racial logic.