Continuing his appeal to Black voters Friday, President Joe Biden commemorated the 70th anniversary of Brown v. Board of Education - the landmark 1954 Supreme Court ruling that desegregated American schools. "You changed the world," Biden told the audience gathered at the African American History Museum in Washington. But Biden said while progress has been made, much more needs to be done. And he called out his likely 2024 challenger, Donald Trump and his allies, for attempting to roll back the decades of progress that have been made. "We have a whole group of people out of there trying to rewrite history, trying to erase history," the president said. "My predecessor and extreme MAGA friends are now going after diversity, equity and inclusion all across America. They want a country for some, not for all," Biden said. "And let's not kid ourselves, folks, this is the God's truth, what I'm saying." Biden's speech was part of a stepped-up effort to highlight his administration's commitment to racial equity and to Black voters more generally in the midst of the 2024 election campaign. Later Friday, he was to host leaders of the “Divine Nine” historically Black sororities and fraternities. On Thursday, Biden met with plaintiffs from the Brown court case in the Oval Office and earlier in the week, courted voters in Atlanta and Milwaukee with a pair of Black radio interviews. On Sunday, he'll give the commencement speech at Morehouse College in Atlanta, one of the historically Black colleges and universities, or HBCUs. The president, facing sagging poll numbers, is seeking to shore up his support within a critical bloc that helped deliver his 2020 victory. Fifty-five percent of Black adults approved of the way he was handling his job as president, according to an AP-NORC Center for Public Affairs Research poll in March, a figure well below those from earlier in his presidency. In the decades since the Brown decision, American schools have been re-segregating. The country is more diverse than it ever has been. Still, around 4 out of 10 Black and Hispanic students attend schools where almost every one of their classmates is another student of color.