THE HILL: Arizona Rep. Grijalva latest incumbent in tough reelection race. “Even liberal Democrats from normally safe districts are embroiled in tough reelection races this cycle. Two recent polls show Rep. Raúl Grijalva (D-Ariz.) — who hasn’t faced a tough challenge in his eight years in the House — within the margin of error against an unknown Republican.

” He’s no rocket scientist — but the “unknown Republican” is.