Despite winning the Louisiana primary election in March, Donald Trump walked away with fewer GOP delegates than Ted Cruz. As you would imagine, the billionaire called the results "a fix" and "rigged."

Last Week Tonight's John Oliver was forced to side with Trump. "I get why he's annoyed. And there is no clearer piece of evidence that our system is broken, no more thoroughly dead canary in the coal mine, than when Donald Trump is actually making sense. When you see results like that, the process does feel counterintuitive."

Related A guide to the presidential primaries

America's bizarre primary system goes back to the 1960s, when the Democrats chose Hubert Humphrey as their nominee despite the fact he hadn't won any primaries. The Democratic convention was chaos, leading to bouts of violence. So both parties decided to reform their systems to make them more democratic.

"But many of the details were left up to state leaders," Oliver said, "which might help explain why we have such an erratic clusterfuck every four years. Almost every part of this process is difficult to understand."

For example, most states hold primary elections in which people vote for a nominee. But several states hold caucuses — essentially meetings in which people convene to argue about who they prefer for the nomination for up to hours, and then vote. As Oliver noted, caucuses "can be prohibitive. Because if you work at night, or you can't get a babysitter, or you don't have transportation, you can be frozen out." As a result, turnout for caucuses tends to be much lower than primary elections.

Then there's the issue of how delegates are selected. In the process, voters aren't just casting a popular vote that will be added up with the rest of the popular vote to select the nominee. Instead, people are voting for delegates who will then pick the nominee at the convention. This is a very important distinction, because states frequently have weird rules for how delegates are divided up.

Consider Nevada: It had a caucus, which Hillary Clinton won, but that only determined 23 out of 35 delegates. Then, the remaining 12 delegates were later picked at a state convention, and those delegates at the state convention were decided by delegates at county conventions, and those delegates at county conventions were chosen in the caucus. So even though Clinton won the caucus, Bernie Sanders supporters persisted enough through the county conventions to nearly seal his overall victory in the state — only to have Clinton pull ahead in the state convention.

"At this point, whoever you support, you probably feel like this," Oliver said, rolling footage of a man screaming.

To top it all off, each party has a way to tilt results in the favor of a certain nominee should they not like the final outcome. For Democrats, that's superdelegates, or unelected delegates (typically party insiders) that can pledge to whomever they want. For Republicans, many delegates from certain states are only required to vote for the candidate they were pledged to during the first round of ballots at the convention — and then they can vote for any candidate they want, allowing them to overturn the expected results. (This is what Cruz hoped would happen versus Trump.)

After all of that, America finally gets two major party candidates for president. "This is a system that clearly needs wholesale reform," Oliver said. He later added, "There's no guarantee that the candidate with the most votes will win next time. And if they don't, all the flaws we just documented will be exposed yet again."

But as Oliver pointed out, people tend to forget about how broken the primary system is after the primary elections are over. So he proposed a day next year for everyone to write into their party leaders to ask for reform: February 2.

"That will be easy to remember, because it's Groundhog day," Oliver said, "which does seem appropriate, because unless this primary process is fixed, we are all destined to live through the same nightmare scenario over and over again until the end of fucking time."

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