Bob Gilbert's fourth novel, "A Firm State of Heart," takes place in Washington, D.C. Its protagonist, Minneapolis writer Samuel Meckler, is crafting a long poem that's trying to rise above the chaos of the Trump presidency. Meckler supports himself by working as a waiter at Tadich Grill, an upscale Washington restaurant located on Pennsylvania Avenue between the White House and the US Capitol. His interaction with congressmen, senators, foreign...