Mr. Seigenthaler talked about his book, James K. Polk, published by Times Books. He described Polk as key to the U.S. westward expansion, and who carried forward the idea of Jacksonian democracy. Polk was the youngest president elected. He served as Speaker of the House and governor of Tennessee before taking office in 1845. The author said he became less admired during his term until he revived his political career by gaining popularity with those who favored annexing the Republic of Texas to the Union.