Rep. Chris Pappas (D-N.H.) and former Sen. John E. Sununu (R-N.H.) are projected to face off against each other for retiring Sen. Jeanne Shaheen’s (D-N.H.) seat in the Granite State, according to Decision Desk HQ. Pappas defeated four other Democrats for the party nod, with his most serious challenger being scientist Karishma Manzur. Meanwhile, Sununu beat…