"The political parties choose their nominees, not the general public, contrary to popular belief," a top Republican Party official explained last month.

That's a hard truth, but a truth nonetheless. Despite its public function, a political party is a private organization, and as a private organization it makes its own rules, it enforces those rules and if it wishes it can change its rules. And in district conventions across the state last weekend, the Georgia Republican Party gave Donald Trump and his backers a taste of what that could mean at the national convention in July.

Back on March 1, Trump won the Georgia GOP primary pretty easily, beating Ted Cruz by 14 percentage points at the ballot box and earning the pledged votes of 42 of Georgia's 76 delegates at the national convention.  However, under party rules that victory did not give Trump the right to decide who those 42 delegates should actually be, meaning that he can't dictate that they be Trump loyalists. Instead, the right to name those delegates was left to Georgia Republicans who attended and ran district conventions Saturday. Most of those who attended were longtime party activists, and most of those whom they elected were also longtime party activists.

The result? Yes, Trump will still get the 42 first-ballot Georgia delegates that are bound to him as a result of the primary. However, if the nomination isn't decided on the first ballot, those 42 delegates will be free to follow their consciences in any subsequent votes. And many of them have already made it clear that given the chance, they will abandon Trump at that point and look elsewhere, probably to Cruz.

It's a pattern being repeated in the delegate-selection process around the country, raising the odds that if Trump doesn't go to Cleveland with close to the 1,237 pledged first-ballot delegates needed to claim the nomination outright, he will be denied the prize he seeks. And delegate selection is just one of uncounted potential ways in which party insiders can attempt to undermine his candidacy.

What will happen if they succeed? How will Trump's supporters react?

“I hope it doesn’t involve violence,” Trump said this weekend. "I hope it doesn’t. I’m not suggesting that. I don’t think it will."

"But I will say this, it’s a rigged system, it’s a crooked system.”

I can see why Trump and his followers would think that.  He has drawn almost 2 million more votes than Cruz, and is certain to pad that lead as well as his delegate lead in tomorrow's New York primary. In addition, the two national polls released this month give him an average lead of 15 points among Republican voters. In any other year, if Trump were any other candidate, he would already have been given the keys to the party. Instead he faces a very real chance of losing, or as he sees it, of being "cheated".

So yes, the system is "rigged" against candidates like him. But it probably ought to be.

The genius of the American system -- the key to its survival for more than two centuries -- is its ability to let the people govern themselves and make their own decisions while ensuring that self-governance does not devolve into mob rule in which the passions of the moment overwhelm common sense. The Founders were deeply fearful of what James Madison, the chief architect of our Constitution, described as "the superior force of an interested and overbearing majority.” As a result, our politics and government are replete with features designed to slow and if necessary frustrate the easy expression of popular passions.

That's why the unwieldy, seemingly anti-democratic Electoral College, not the popular vote, was made the deciding factor in presidential elections. That's why the Bill of Rights forbids the majority from infringing upon, abridging or disparaging the basic rights of the minority. The presidential veto exists as a check on temporary passions that might sweep through a legislative body, and the Supreme Court is given the power to override both Congress and the president if populist pressures push them to unconstitutional action.

The political parties have installed similar checks on populist passions, designed to require second thoughts or even third thoughts before rash action can be taken. That's what Trump and Bernie Sanders are both running up against, and if those roadblocks are frustrating to those intent on carrying out a revolution ... well, that's by design. They don't make a successful revolution impossible, but they do make it difficult.

That's a feature, not a bug, and it's a feature worth defending.