https://www.ted.com/talks/lawrence_lessig_we_the_people_and_the_republic_we_must_reclaim?language=en
In a crude primary process, America has ended up with two candidates the majority of Americans don't like. Rather than add to the volumes written about Trump and Clinton we can instead look at the guy that probably would have won easily against Trump, yet got one of the lowest vote tally ever in a 3-way primary, Martin O'Malley who scored just above 0% in his last primary before he quit the race.
Martin is the ideal democrat and even has some conservative bents.
He's been a very successful governor of a medium sized state with success in all major metrics (Crime, education, guns etc). As a democrat, he is a perfect centrist. Admittedly, he didn't get far enough to have all his baggage aired, but, assuming nothing damning was found, would have easily beaten Trump in a general election, since he did not evince the same visceral resentment shown towards Hillary Clinton, who has been famous and in politics so long that she has a lot of baggage.
The press dismissed his bid for presidency as "he didn't get enough party support" or "he didn't get enough money" But in reality, he just didn't get enough press, which makes the media's argument a self fulfilling prophesy. Sanders had the same disadvantages (no endorsements and minimum money at the start) but he was propped up with a populist extreme message which was highly newsworthy that gave him the exposure (money followed). Could Obama have been elected if he wasn't that bit extra news-worth by being african american. Could George Bush has been elected if he wasn't from the famous clan. Could Hillary be elected if she wasn't a Clinton. Back when no one knew Bill Clinton, could he have won the primary if he wasn't up against equally unknown candidates, since the party stars didn't think they could win against the (temporarily) very popular incumbent George H W Bush? Perhaps he wouldn't have won if he didn't have the Jennifer Flowers scandal that made him much more famous.
Are we simply supposed to assume the non-democratic view that "hey, if they are not already famous, or can't create sensationalist press headlines, then the system disqualifies them from being President". Britain just got another prime minister who was colorless in the press and who's main claim to fame was being a competent Home Secretary, a relatively technical job, so it does not seems to be a universal law.
So Martin O'Malley (or John Kasich for the Conservatives) would probably win a general election more easily than Hillary Clinton but decisions were made early in the process that precluded him from getting party support and press exposure. How were those decisions made and who made them? More importantly, is it a structural part of the system and are we condemned to only famous or extreme people forever.
Neither door was open to O'Malley. He didn't eviscerate Hillary onstage. He didn't propose a a giant wall or free college. He was not newsworthy since his plans were sensible, practical and modest. Bernie Sanders however, even without support from the party elders, could get headlines with his scathing attacks on Hillary and the revolutionary talk of turning the U.S.A. into Denmark with as much "free everything" as possible and punishment for the 1%.
So how can a competent centrist (who is not famous already) win the primary? It appears they can't. Parliamentary systems depend on impressing (and rewarding) insiders to get the job, whereas winning the presidency is about winning sound bites, and if you are not already famous, the most outrageous sound bites. So the first round of the selection process is determined by how many papers you can sell.
