But the night was defined by the contrast between Sanders and Warren on the left and four thoroughly obscure hopefuls from what was once the party’s middle: former Colorado governor John Hickenlooper, Montana governor Steve Bullock, congressman Tim Ryan of Ohio, and former Maryland congressman John Delaney. While senators Sanders and Warren represent solidly blue Vermont and Massachusetts, Hickenlooper, Bullock, and Ryan are the kinds of Democrats one still finds in competitive states in the West and Midwest, while Delaney stands out for the great wealth he acquired as a businessman at the intersection of the finance and pharmaceutical industries. Delaney argued that Sanders and Warren simply do not understand America’s healthcare system, and their proposed fixes for it would be financially and politically disastrous, stripping Americans of their private insurance. Warren chided him accepting that the healthcare game must be played by the rules set by the industry, rather than by visionary politicians like herself or the senator from Vermont. (Bernie, for his part, dismissed Delaney’s business experience by saying that healthcare shouldn’t be a business.) Ryan, Hickenlooper, and Bullock added to the attacks on the paladins of the left, but didn’t make as much of an impression as Delaney, who seemed at times to be playing a role of deliberate spoiler — or perhaps ringer for Joe Biden, if not the RNC.

None of the centrist critics has the slightest chance of winning the nomination, but they underscore a serious problem for ambitious left-wingers like Warren and Sanders. Congress is full of Democrats like Bullock, Hickenlooper, Ryan, and Delaney, and the party’s survival in red, pink, and purple states still depends on such moderates. When Barack Obama won the White House the first time in 2008, he had Democratic majorities in both houses of Congress, and his margin of popular victory was enough that in theory he had a real mandate. Yet the most Obama, with all that political capital, could achieve was the passage of a healthcare reform modeled after the plan enacted by a Republican governor in Massachusetts four years earlier. Should Sanders or Warren win next year’s election, the odds are he or she will still have to contend with a Republican Senate. Yet even if the Democrats were to take the Senate, what kind of Democrats would hold the balance of power? Enough Democrats of the Delaney type to make a ‘political revolution’ of the sort Sanders called for a dead letter from day one.