An embattled Mayor Bill de Blasio took to Rev. Al Sharpton’s pulpit Saturday to talk about the forces opposition. “The voices of the status quo find many, many ways to undermine progress, to stand in the way of progress,” he told a crowd at the National Action Network in Harlem. “But we will not be held back. We will not be held down. We’ll keep moving forward.” de Blasio never explicitly mentioned the ongoing federal and local criminal probes of his Campaign for One New York nonprofit and his 2014 fundraising for state Senate Democrats. After the event, he hustled past reporters without commenting on the scandals enveloping City Hall.