The Democrats' Super Tuesday results were less contentious insofar as Hillary Clinton did as expected, winning solidly in delegate-rich states like Texas, Georgia and Massachusetts. Bernie Sanders won in Colorado, Oklahoma, Minnesota and his home state of Vermont, and though the plucky New Englander has vowed to fight on to convention day in Philadelphia, Ms Clinton appears to have the nomination all but locked up. It's not a prospect that pleases all Democratic party supporters – Ms Clinton's campaigning and rhetoric has been leaden and uninspiring, she is regarded as uncomfortably beholden to corporate and establishment interests, and she's seen as carrying more baggage than a travelling potentate.

Mr Trump's momentum is now such that it's hard to conceive of any of his opponents paring back his lead. Some commentators suggest Senator Rubio is best placed to deny the New Yorker the nomination, but that this would only occur if Republican wheelers and dealers brokered a deal at the national convention in July, an undemocratic outcome that hasn't occurred in decades.

If fact, more and more Republican leaders appear to be resigning themselves to a Trump nomination, if reluctantly. Before Tuesday's results were posted, Senate majority leader Mitch McConnell and House speaker Paul Ryan said they would back Mr Trump as the GOP's nominee, even though they criticised him for not distancing himself from former Ku Klux Klan grand wizard David Duke.

Mr Trump's ability to win and hold public support while offering little in the way of constructive policies – and while demonstrating a penchant for bigotry and crude populism on the stump – has been the talk of this presidential race. That he's cannily exploited the resentments and frustrations of less well-educated and privileged Americans is certainly true. But Mr Trump's victories in the liberal New England strongholds of Massachusetts and Vermont suggest his appeal is broader than most of his critics may have previously allowed.

American political history is replete with crude populists, though none has actually ever become president, probably because (as Abraham Lincoln said), "you cannot fool all the people all the time". That the party of Lincoln might yet nominate Mr Trump as its presidential nominee is indeed ironic.

If Mr Trump were to became president (and this seems highly improbable given the far safer option represented by Ms Clinton) America's very effective system of checks would probably save him from himself. But if he wins the nomination and fails dismally against Ms Clinton, nothing may save the Republican party.