Joe Trippi, formerly the Chief Strategist on John Edwards' campaign, disclosed in a piece in Campaigns and Elections that he has some regrets about not telling Edwards to stay in the race.
I didn't tell him what I should have told him: That I had this feeling that if he stayed in the race he would win 300 or so delegates by Super Tuesday and have maybe a one-in-five chance of forcing a brokered convention.

I should have closed my eyes to the pain I saw around me on the campaign bus, including my own. I should have told him emphatically that he should stay in. My regret that I did not do so-that I let John Edwards down-grows with every day that the fight between Hillary ClintonHillary Diane Rodham ClintonGeorge Takei: US has hit a new low under Trump Democrats slam Puerto Rico governor over 'shameful' comments, back protesters Matt Gaetz ahead of Mueller hearing: 'We are going to reelect the president' MORE and Barack ObamaBarack Hussein ObamaMichelle Obama weighs in on Trump, 'Squad' feud: 'Not my America or your America. It's our America' Media cried wolf: Calling every Republican a racist lost its bite Rubio criticizes reporters, Democrat for racism accusations against McCain MORE continues.