Risk or safety? The dividing line between Joe Biden and his challengers.

He may be running on the Obama record, but the promise of Biden’s third presidential campaign is entirely different. Despite an uneven performance, he has found success by pitching himself as the safe, comforting and electable caretaker, an implicit contrast to potentially riskier rivals who are less well known, have less experience and are offering more disruptive policy platforms. "Most primary voters are not making their choice based on ideology. They are looking for a strong candidate who can run a steady campaign and appeal to voters broadly,” said Anna Greenberg, a Democratic pollster who surveyed for former Colorado governor John Hickenlooper, who departed the race last month. “There are many candidates who could fit this description.”