Fuck me, I thought Putin was based
Most here have read it. In the book, the POTUS was determined to hold together the union. Congress was determined to split it apart on irreconcilable differences. POTUS showed up on the final speech to make one last plea for sanity, but a bomber blew up the building during the speech. The vote continued as scheduled, POTUS having failed to plead his case. The US was broken up, hence "the last president".