Forty-five years from the day they were elected to write a new Illinois Constitution, several delegates and convention staffers reunited Tuesday to reflect on their time spent crafting the structure for state government. On Nov. 18, 1969, voters across Illinois chose 116 delegates to write the state’s first new constitution since 1870. They would meet in Springfield a few weeks later.Ann M. Lousin, a longtime professor at The John Marshall Law School, participated in the constitutional convention &mdash …