Possible Clues:

• He called the U.S. vice presidency a 'most insignificant office'
• Novel cleric offers Nabokov heroine on written document
• Singer Edie
• Bryan --, Canadian rock singer and guitarist
• Presidential surname
• He followed Monroe
• U.S. president #2
• A fruit's not acceptable for the president
• & 16 Across Lump in one's throat as water pipe oddly cracks
• 'Dilbert' cartoonist Scott