Former first lady Michelle Obama has said she will “never forgive” Donald Trump for stoking far-right “birtherism” theories about then-President Obama during his campaign. In her new memoir, Becoming, Obama writes that she was shocked when Trump became president and tried to “block it all out,” according to The Washington Post. The former first lady says she reserved special disdain for Trump for his claims that Barack Obama was not born a U.S. citizen. “The whole [birther] thing was crazy and mean-spirited, of course, its underlying bigotry and xenophobia hardly concealed. But it was also dangerous, deliberately meant to stir up the wingnuts and kooks,” she wrote. “What if someone with an unstable mind loaded a gun and drove to Washington? What if that person went looking for our girls? Donald Trump, with his loud and reckless innuendos, was putting my family’s safety at risk,” she said.