Two Boston School Committee members, including the chairwoman, have resigned after text messages disparaging parents of students as “delusional” and “racist” were made public. The texts were sent last October during a public debate on whether the city’s three prestigious public schools will continue to use an entrance exam to select students or decide eligibility based on students’ grades and zip codes. Dozens of parents, mostly white and Asian, spoke against the proposal, saying it would undermine those schools’ reputation of academic excellence. “Best school committee meeting ever. I’m trying not to cry,” school committee Chair Alexandra Oliver-Davila said in a text to fellow committee member Lorna Rivera, according to the texts obtained by the Boston Globe via a public records request. “Wait until the white racists start yelling at us,” Rivera replied. “Whatever. They’re delusional,” texted Oliver-Davila in response. “I hate WR,” she wrote, a reference to West Roxbury, …