This late in the race for the Democratic presidential nomination, it is something of a mathematical implausibility for Bernie Sanders to win. With only a handful of states still left to be contested in the month of May, whilst it's probably impossible for Hillary Clinton to win the nomination before California, unless something utterly strange happens, then the result in California is only likely to confirm what we already expect.
Considering that Cruz has now officially suspended his campaign and Kasich has also officially suspended his, Trump's nomination is something of a fait accompli. The remaining primaries on the Republican side of the contest are all walkovers.
This being the case, the most likely matchup for the Presidential election on November 8 is Trump v Clinton and in that light, comments by Donald Trump only serve to highlight one of the massive flaws of the voting system used in the United States. Trump said that Bernie (and himself) had been treated poorly by the system and that Bernie should consider running as a third party candidate.
Now the reason why Trump in particular should want Bernie Sanders to run as a third party candidate is precisely the same reason why the Republican Party practically begged him to run as a Republican in the first place. The first-past-the-post system is inherently dumb.
The first-past-the-post system is in my opinion, incorrectly named. This name implies that there is a metaphorical post, which has to be passed when there isn't really. Under the first-past-the-post system, one only needs to win more votes than anyone else. The system should properly be called the most-votes-wins system. If there was say, a really close race between four candidates, then it is possible for the winner to have only achieved 26% of the vote. A candidate might win despite almost three quarters of the votes passing to other people.
Consider the following scenario in the election of a member from the state of Animalia:
Alison Albright (All Animals) - 24 votes
Bert Bash (Burn All The Animals) - 26 votes
Carl Castle (Cats Are Cool) - 25 votes
Dorothy Dixer (Destructive Doggies) - 25 votes
In such an election, a candidate hated by almost three quarters of the population would win and yet that's somehow a legitimate result. Conceivably in the next election cycle, A & D might team up to create a bigger bloc and suddenly because C & D hate each other, then C which might have anti-D policies, is going to join the bloc with B.
To some degree this has happened over many election cycles in the United States (and everywhere with single member constituencies) but the most-votes-wins voting system only helps to exacerbate the problem. Donald Trump's comments about Bernie Sanders running as a third party candidate would help him in a general election by splitting the Democratic vote in half. For the same reason, the Republicans had to have Trump run as a Republican or else he'd split their vote.
A preferential voting system solves both this problem as well as changing the nature of the philosophy of the vote. It is no longer about who can gather the most votes but requires the consent of the governed at some point down the line.
Arguably the nomination race for President is like two rounds of voting but that still doesn't change the fact that the voting public have to accept the final nomination. A first-past-the-post system works if you have only two runners, or if one candidate does manage to secure more than 50% of the vote but a preferential voting system allows for the consent of the governed to determine the result of an election, rather than the will of the hyper vocal and possibly unhinged portion of the population.
Had there been a system in place where voters could select who they wanted on a preferential basis, then on a nationwide basis (which also would do away with the arcane and completely bonkers Electoral College) then you could in effect, condense the entire process of primaries into a single piece of paper and instead of the 119 day marlakey to find "the nominee" of the respective parties and then wait another 154 days for the general election, you could do the whole stinking shebang in one day.
Instant-Runoff Voting is excellent because as the name suggests, all rounds are instantly run off and you also work out who has secured more than 50% of the vote by consent; rather than most votes wins. You could save billions of dollars in wasted advertising, in time and effort.
This all could have been solved with far less effort, pain and cost. Instead, the process has thrown up the least "popular" candidates in my lifetime and candidates with the lowest approval rating in my lifetime. Even in 1984 when Ronald Reagan painted the nation red, Walter Mondale who ran against him (and was Carter's Vice President four years earlier) still had approval ratings in the mid 50s. Trump is trending at mid 30s as is Hillary.
Had an Instant-Runoff Voting system been in place, then people could have voted for both sides at once in a general election and note split the vote. As it is, we're looking on as America sleepwalks into a firey furnace and there's no one around to guide them out again.