By Andrea Shalal WASHINGTON (Reuters) - President Joe Biden took aim on Sunday at the "ugly poisons" of "systemic racism and white supremacy" that he said had long plagued the United States, and vowed to change the laws that enabled continued discrimination. In blunt language, the Democratic president said the country faced problems with racism, xenophobia and nativism. Biden's statement followed similar sentiments from Vice President Kamala Harris, who detailed in Atlanta on Friday the U.S history of discrimination against Asian Americans. "Racism is real in America and it has always been," s...