New York ? As the fight over immigration reform drags on, an ominous undercurrent to the debate – racism – is becoming more pronounced.

From muttered ethnic slurs to violent attacks, activists say an anti-immigrant backlash seems to be growing in America’s neighborhoods and workplaces. A few political leaders have called proposed immigration measures before Congress “racist.”

“The climate has gotten demonstrably worse and it is racially charged,” said Devin Burghart of the Center for New Community, which tracks anti-immigrant activity. “It’s not simply a debate about immigration policy. … It’s about race and national identity and who and what we are as Americans.”

Some activists say the House of Representatives started it.

When lawmakers passed a bill in December that would make illegal immigrants felons, many felt that was a swipe at Latinos, who make up 80 percent of the nation’s estimated 11 million illegal immigrants. Former President Jimmy Carter has said the bill had “racist overtones,” and that feeling helped push more than 1 million demonstrators to attend street rallies in recent months.

Some reacted the same way after the Senate passed an amendment to its immigration bill last month that declared English the national language. Senate Minority Leader Harry Reid, a Nevada Democrat, called that “racist” and “divisive.”

The amendment’s sponsor, Oklahoma Republican Sen. James Inhofe, replied that Reid’s statements were “ridiculous.” Republican Rep. James Sensenbrenner of Wisconsin, who wrote much of the House bill, issued a study on six countries’ immigration policies and found that five – including Mexico – make illegal entry into their nation a criminal offense.

But Luis Valenzuela, of the Long Island Immigration Alliance in New York, said the measures feel hostile to many immigrants. The bills “set (an) overall climate which is quite racist,” he said. “That elicits action by extremists.”

Mark Potok of the Southern Poverty Law Center, which has tracked hate crimes for decades, said that hate groups “consistently try and exploit any public discussion that has some kind of racial angle, and immigration has worked for hate groups in America better than any issue in years.”

The Anti-Defamation League, a nonprofit that fights anti-Semitism and other bias, put out a report last month that said “hateful and racist rhetoric” aimed at Latino immigrants had grown “to a level unprecedented in recent years.”

The report did not give an overall figure for hate speech and hate crimes, but detailed numerous examples including:

¢ Two men in Tennessee who were sentenced to prison in December for shattering windows and painting Nazi symbols in a local Mexican market.

¢ Internet video games, such as one called “Border Patrol,” urge players to shoot characters drawn as Latino caricatures.

¢ New Jersey Internet radio talk show host Hal Turner posted an “ethnic cleansing manual” on his Web site days after the massive May 1 protests.

Sociologist Gonzalo Santos of California State University at Bakersfield said immigration is just the latest example of social policy issues taking on racial overtones in America.

“People talk about immigration as if race doesn’t matter, saying ‘No, I don’t have anything against immigrants or Mexicans, it’s just the illegal part of it I don’t like.’ But those are code words,” he said. “We experience race in this country through issues like welfare policy, anti-poverty programs and now immigration.”