Whatever party is out of power, or whatever faction feels out of power (even when the party they support is in power) -- they want to manufacture public outrage and make people believe that the system is unfair. The idea that the White House is "purchased" by "money in politics" and "the one percent" is a propaganda trope, nothing more.
People seem to forget that Hillary Clinton's campaign and supporters out-spent Donald Trump's campaign and supporters, two to one. Trump did not have any public endorsements from prominent celebrities, Wall Street or Silicon Valley tycoons, people considered "elite" in American society. (Peter Thiel was an exception.)
Source: Did Hillary Clinton outspend Trump
On the other side, one recalls that Alexandria Ocasio-Cortez was a bartender from the Bronx. She had no prior political activities, and was discovered, as luck would have it, by a handful of former Bernie Sanders' campaign staffers who wanted to replace an incumbent Democrat from a safe Democratic district. She spent almost nothing and successfully won a primary challenge against a very well-connected sitting Congressman with several committee positions. She is not president, obviously, but she at least has enough name recognition to eventually become a presidential contender.
My personal opinion is that, although voters tend to respect candidates who appear accomplished and have the trappings of success, there is no price tag on the presidency. The age of social media, and widespread disillusionment with the party establishments, mean that electoral power is basically up for grabs to any sufficiently motivated and charismatic individual(s), as Trump and Ms. Cortez have both proven beyond doubt.