WASHINGTON - A white supremacist's recent shooting attack at the US Holocaust Memorial Museum was part of a surge in extremist activity nationwide, according to Morris Dees. White supremacist groups are increasingly relying on US military training, Dees, co-founder of the Southern Poverty Law Center, which works to track and shut down hate groups across America, said on Friday. Speaking at a luncheon at the National Press Club, he discussed the findings of a report the Law Center released that day. "Large numbers of potentially violent neo-Nazi skinheads and others are now learning the art of warfare in the United States military," Dees said. Along with the report, the Law Center sent Congress a letter urging the investigation of how racist organizations are "infiltrating" the military. Dees identified two ways in which hate groups take advantage of military training. Some extremists enter the armed forces to learn skills they will later take back to their groups, while in other instances, these groups work to recruit frustrated veterans. Beyond the military, Dees said his organization sees a rise in hate groups, and it now lists more than 900. "Hate groups are on the rise in the United States," he said. "The 'perfect storm' is brewing for the buildup of these hate groups." Anger over the election of a black president, the failing economy and Latino immigration are all causing this phenomenon, he explained. He added that at the heart of most of these hate groups is a simple belief that "Jews are the enemy." For instance, James von Brunn, who shot security guard Stephen Johns at the Holocaust Museum, blamed the Jews for the decline of the white race and had written that "Obama was created by the Jews. Obama does what his Jew owners say." The bad economy has also led these extremists to use minorities as scapegoats for financial hardships, Dees said. Finally, the newest issue for hate groups is immigration. "The Latino population in this country, documented or otherwise, is the biggest engine generating increase in hate groups," he said. Dees, whose organization has taken millions of dollars from hate groups via court cases, ran through many examples of recent hate crimes, murders and foiled plots. While Dees spends his days studying and fighting hateful extremists, the man who grew up in segregated Alabama sees the progress the US has made and is hopeful about the future. "There undoubtedly are going be more acts of violence that we're going to have to put up with," he said, adding that despite this, "I feel positive that this nation is not going to go back, we're going to go forward."