He hasn’t declared, yet, but Hill is a dinosaur. He turns 64 in 2017, not exactly the age to begin a Senate career.
According to Politics1, these are the other speculative Dem candidates (incl. ex-Sen. Bayh):
Evan Bayh (D) - Ex-US Senator, Ex-Governor, Ex-Sec. of State & ‘08 Presidential Candidate
Brad Ellsworth (D) - Ex-Congressman, Ex-Vanderburgh County Sheriff & ‘10 Nominee
Christina Hale (D) - State Rep.
Baron Hill (D) - Ex-Congressman & Ex-State Rep.
Tom McDermott (D) - Hammond Mayor, Attorney & Navy Veteran
Bart Peterson (D) - Ex-Indianapolis Mayor, Pharmaceutical Executive, Ex-Gubernatorial Aide & Attorney
Glenda Ritz (D) - State Supt. of Public Instruction & Ex-Teacher
While 64 may be too old to embark upon a three-term Senate career, it wouldn’t stop Hill from running if he thought that he’d have a shot at winning.
Ellsworth would be the most Donnelly-like nominee, and could win if the GOP nominee messes up.