Donald Trump. AP If Donald Trump arrives at the Republican National Convention with less than a majority of delegates bound to him, his message will be simple: I got way more votes than anyone else, and party insiders are conspiring against me to give the nomination to somebody else.

This complaint will be true, it will be valid, and anti-Trump Republicans will dismiss it at their peril.

There has been a weird epidemic of shortsighted schadenfreude among Republican insiders over the past week as they watch Trump's campaign blunder through the intricacies of delegate selection.

It is true that Trump's campaign is doing badly at the small stuff, and it's costing him delegates. Trump failed to organize for Colorado's complex delegate conventions, in which voters never got to express a direct preference for a candidate. He has just started the process of selecting hundreds of delegate candidates in California. He has failed to stack relevant convention committees with his allies.

When Trump has called the nominating rules a "scam" and a "disgrace," the response has been mainly that he should stop whining. Here's Reince Priebus, chairman of the RNC:

But here's the thing: Democratic legitimacy is not just about following the rules as written. It's about having a set of rules designed to produce a result in line with voter preferences. In some states, the Republican nominating rules are designed to ignore the will of the voters.

Trump is right: These states' rules are a scam, and saying so is not whining.

Take Colorado, for example. Voters in Colorado didn't get to vote in a primary or a caucus because the state's Republican Party executive committee decided last summer not to hold any presidential preference vote. Instead, voters had to gather at far-flung, time-consuming conventions to choose individual delegates.

Why wasn't there a caucus with a presidential vote as Colorado had held in previous years? Because this time the RNC had ordered states to bind their delegates to actually vote in line with voters' presidential preference. Colorado Republicans didn't want to do that, so they got rid of the presidential vote.

That is, the purpose of Colorado's rule change was explicitly antidemocratic. It took power away from regular voters and handed it to the sort of activists who would be likely to spend a lot of time and energy participating in party conventions.

These were the rules, but they weren't democratic rules.

RNC Chairman Reince Priebus. Thomson Reuters

Similarly, North Dakota chose to disenfranchise its voters by holding no presidential vote and electing delegates at a convention. Pennsylvania voters will vote for a presidential candidate, but will also have to choose unbound delegates from a list of names, a system designed to put voters in a position of flying blind and choosing representatives to the convention whose intentions are unknown.

These are not systems designed to reflect the voters' presidential preference. If you think the nominating process should be democratic, you could well call them disgraceful, as Trump has.

Now, think ahead to a convention, and the arguments that will inevitably ensue if Trump's popular-vote lead does not translate into a nomination.

Trump will point to the Colorado delegation and say it's illegitimate — that the voters of Colorado were disenfranchised because they never actually got to vote for a presidential candidate. Cruz will say that rules are rules, and these rules were unanimously adopted by the Colorado Republican Party executive committee all the way back in August 2015.

The latter argument will certainly be good enough to get the Colorado delegates — all of whom support Cruz — credentialed at the convention. But it will not be good enough to convince Trump's supporters that he lost fair and square.

The perception of legitimacy is important. A political party is a voluntary association, and Trump's voters have no obligation to stay Republican or support Republican candidates. If he is seen as having lost because of rigged rules, anti-Trump Republicans will win a Pyrrhic victory, as many of his backers will walk away in the general election.

If that happens, the only group enjoying schadenfreude will be Democrats.