On Friday afternoon, Donald Trump’s campaign officially announced the presumptive Republican nominee will not debate Bernie Sanders, despite what Trump had said earlier, because it would be “inappropriate” for the GOP candidate to “debate the second place finisher.”

And if there’s one thing Donald Trump is concerned about, it’s avoiding anything that might be perceived as “inappropriate.”

But in issuing the candidate’s position on the matter, Trump also said what many of the Vermont senator’s most ardent supporters fervently believe: the Democratic nominating process is “totally rigged” against Sanders.

Does the senator himself believe this? CBS’s John Dickerson asked Sanders for his perspective on “Face the Nation” aired on Sunday, and the candidate’s answer seemed quite fair.

“What has upset me, and what I think is – I wouldn’t use the word rigged, because we knew what the words were – but what is really dumb is that you have closed primaries, like in New York state, where three million people who are Democrats or Republicans could not participate, where you have situation where over 400 superdelegates came on board Clinton’s campaign before anybody else was in the race, eight months before the first vote was cast. “That’s not rigged. I think it’s just a dumb process which has certainly disadvantaged our campaign.”

I suspect the response might have disappointed some Sanders supporters who are heavily invested in the idea that the system has been manipulated, deliberately, by party officials for the express purpose of making it impossible for the senator to prevail, but Sanders’ response on Sunday made a fair amount of sense.

It may seem pointless, but it’s worth appreciating the difference between a process that’s “rigged” and one in which an underdog faces institutional challenges that are difficult to overcome.

“Rigged” implies some kind of nefarious scheme, tilting the playing field to ensure a predetermined outcome. In this sense, there’s nothing “rigged” about the race for the Democratic nomination: both Bernie Sanders and Hillary Clinton were aware of the lay of the land in advance; both understood what it would take to succeed; both created game plans based on the existing rules, and both recognized that those rules, some of which were established years in advance, would remain unaltered once the process began in earnest.

In other words, as Sanders himself now acknowledges, the fix wasn’t in. The Sanders and Clinton campaigns played by the agreed upon rules, and one campaign appears to have come out on top by earning more pledged delegates, superdelegates, votes, and contests.

It’s precisely what made the senator’s comments on Sunday so noteworthy: Sanders doesn’t see a conspiracy or nefarious scheme, but he does see a “dumb” nominating process in need of reform. Is he right? Maybe! In Democratic politics, I suspect there are very few people who would look at the existing system and say it’s 100% flawless and any proposed changes must be rejected out of hand.

Indeed, if Sanders and his backers want to take this opportunity to push for changes – to the system of superdelegates, to caucuses, to the registration process, to the state convention process, to opening nominating contests up to Republicans and Independents, etc. – there’s every reason for the party to have a spirited debate. There’s evidence that suggests Clinton would have come out on top under alternative processes – more Democrats want her to be the Democratic nominee – but what matters is the underlying principle, not embracing the scenario that changes the results in an ideologically satisfying way.