LOVE and the US presidency: the two things that money cannot buy if the Super Tuesday primaries are any guide. Despite spending half a billion dollars, Mike Bloomberg proved about as popular among Democrats as Trump’s MAGA (Make America Great Again) hats.

The former mayor of New York had planned to defy convention by entering the race at a later stage and cleaning up. It was a rational, efficient strategy, exactly what one would expect from a self-made billionaire, but elections do not run like that. Sooner or later you have to put yourself up and risk being taken down. In Mr Bloomberg’s case, fellow hopeful Elizabeth Warren did that in blistering style during the Las Vegas debate, and the voters had their say on Tuesday.

Super Tuesday has narrowed the field to two contenders for the Democratic nomination: Joe Biden and Bernie Sanders. The centrist candidate versus that rarest of birds in American political life, the democratic socialist. Mr Biden promising a return to pre-Trump peace, quiet and “decency”, against Mr Sanders’ rebel yells of revolution and taxing the rich till the pips squeak.

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Now that the former Vice-President is back in the running after a dreadful start, there is a sense among the richest Democrats, those the novelist Holly Peterson calls “limousine liberals”, that order is being restored and not a moment too soon. The big name endorsements are flowing in and Mr Biden is looking like a shoo-in for the nomination. On many a measure he might be a safer bet. Yet what Democrats in their quiet moments must be asking themselves is whether he is the best man for the job of not just defeating Donald Trump but reuniting the country. Make America one again, if you like.

That man could never be Mr Sanders, right? Opting for him would be to allow Democrat history of the sorriest kind to repeat itself. Yes, it is customary at this point in proceedings to call to the stand the late George McGovern. Poor Senator McGovern, destined forever to be used as a cautionary tale in an argument with anyone crazy enough to imagine that America would vote for a left-leaning President. Look what happened to McGovern in the 1972 presidential campaign, say the prosecution. Anti-war, pro-fairness, equality, access to free health care, the environment, cutting military spending, all that old time liberal religion.

Here is what Mr McGovern said in his 2011 book, What it Means to be a Democrat: “We are the party that believes we can’t let the strong kick aside the weak. Our party believes that poor children should be as well educated as those from wealthy families. We believe that everyone should pay their fair share of taxes and that everyone should have access to health care.” Who, seeking a civilised society, could argue against this?

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But come polling day, Americans could not vote fast enough for McGovern’s Republican opponent, one Richard Nixon Esq. In 2016, Hillary Clinton had 232 electoral college votes compared to Mr Trump’s 306. In 1972, the split was 17 to 520 in favour of Nixon. A wipeout. Ever since the message has taken hold: the only place mainstream America likes red is in its flag, right beside the white and blue.

But that was half a century ago. The face of America has changed. It is older but more diverse, it has been through wars and come out badly, it has endured global economic recession and seen the gap between the haves and the have nots, the one percenters and the rest, grow to obscene levels. The long-haired young man standing beside Mr McGovern in old photos, campaign aide Bill Clinton, won two presidencies. The country has had its first African-American president, and nearly its first woman commander-in-chief (Hillary won the popular vote).

Not only has America changed in fundamental ways since 1972, Mr Sanders has a better organised and funded campaign that has managed to withstand myriad attacks on it not just in this electoral run but in the last one. Senator McGovern’s campaign, in contrast, was chaotic, his tactics poor and his choices, not least of a running mate, worse.

The only area in which Mr Sanders bears comparison to Mr McGovern is in personal standing. The latter was a decorated war hero and a fundamentally decent man, as scandal free compared to Nixon as Mr Sanders is to the current occupant of the White House.

Though he will loathe the comparison, messrs Sanders and Trump are not that different. Both outsiders, both populist, both with a fiercely loyal base. To beat a populist, send a populist.

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Given all this, if America, almost a century on from the New Deal, is not ready now to give the likes of Mr Sanders a chance, it might never be. Mr Biden is the preferred choice of the party elite, but he is not without controversy. He could be as muddied by Ukraine as Mr Trump. The criticisms levied at the former Veep before Super Tuesday, that he lacked energy and ideas and was too quick to become dispirited when the going got rough, remain. This will be Mr Biden’s third try at becoming president, remember.

Yet how many, hand on heart, can see first the Democrats, then the country, opting for Mr Sanders? It would seem too great a gamble when the economy is powering ahead as it is. The economy will be at the centre of the 2020 race for the White House as surely as it has been in every other contest in the modern age. The Republicans will be dusting off Reagan’s famous question, “Are you better off now than you were four years ago?” and deploying it mercilessly. Mr Trump’s basic stump speech, save for changes every now and then when he acquires a new object of ridicule, is all about the economy.

He is not unbeatable. His popularity ratings continue to bump along the bottom compared to others in the job at this stage of their presidencies. But it will not be easy. Oh for a Democrat candidate who had Bloomberg’s money, Sanders’ verve, and Biden’s reassuring blandness. The Democrats have the potential to win. That is not in doubt. Whether they can put their differences aside and unite behind one man is something else.