"If I did a 10th, a 10th of what [Hillary Clinton] did," Michael Flynn said at the Republican convention, "I would be in jail today."

Well, Flynn is not in jail today, but he only managed to avoid it by pleading guilty to the charge of lying to the FBI about his contacts with the Russian ambassador and agreeing to cooperate with Special Counsel Robert Mueller's investigation into the Russia scandal. In other words, the former national security adviser is singing, and President Trump is in serious trouble.

Which I'm sure makes Trump feel terribly betrayed. After everything he did for Flynn, this is the thanks he gets? How about showing some loyalty?

Loyalty, though, is a tricky thing in politics. Everyone around the politician is expected to show absolute loyalty to him, but nobody really expects him to be loyal to them. They all understand that it's a one-way street: You're there to serve the guy whose picture is on all the posters, but to him you're just one of many whose purpose is first to help him get a job, and then to help him succeed in it. You're expected to work unspeakably long hours, ignore your family, extol your boss' virtues to all who will listen, even to lie for him (something Trump aides have to do an awful lot). Yet if you embarrass him even for a second, you can expect him to toss you to the curb.

Yet Trump did show something like loyalty to Flynn. After acting Attorney General Sally Yates informed the White House that Flynn had lied to the FBI, it took Trump 18 days before he finally fired him — and then he immediately began praising him to the press. According to former FBI Director James Comey, Trump asked him to lay off Flynn. White House officials reportedly asked high-ranking intelligence officials if they could intervene with Comey to get him to back off the former national security adviser. It appeared that Trump was desperate to protect him.

It's hard to believe that Flynn would have been naïve enough to believe that was all because Trump just liked him so much. We're talking about Donald Trump, an almost comically self-centered man who has shown ample willingness to screw just about anybody over in pursuit of his own interests. So it may not be surprising that Flynn eventually decided that he had to look out for himself. With prosecutors closing in and the extent of Flynn's legal exposure becoming clear, his calculation seemed to change. As ABC News reported, "Flynn felt abandoned by Trump in recent weeks, and told friends about the decision to make the plea deal within the last 24 hours as he grew increasingly concerned about crippling legal costs he would face if he continued to contest the charges."

Flynn is now the second cooperating witness in Mueller's investigation, after former campaign adviser George Papadopoulos. But he may not be the last. Because while it's a lot to ask for anyone to go to jail rather than implicate their boss, Trump is particularly susceptible to having his aides turn on him when it's in their own interest. Because he didn't make the long political ascent most presidents do, he doesn't have around him a cadre of aides who have been with him for years or decades, apart from a couple who came with him from his real estate days. Most of those working for Trump are either mercenaries looking to advance their own careers, ideologues who have an agenda Trump may barely share or even understand, or party apparatchiks who would be working for any Republican.

How many of them are going to take a legal bullet for Trump? Not many — especially when he's such a nightmare to work for, his ignorance and capriciousness making their lives more difficult by the day. In previous White Houses you'd find a staff that worshiped their boss as both a politician and a person, but few of Trump's aides seem to have the same regard for him.

Even in those earlier administrations, there were those who got disillusioned and became willing to publicly oppose their boss, whether because of policy decisions they disagreed with or a moral failing they couldn't abide. Barack Obama was largely an exception — nobody wrote a scandalous tell-all about life in his employ or helped a reporter write one, although there were such books about Ronald Reagan, Bill Clinton, and George W. Bush. The latter was even called The Price of Loyalty.

We'll probably get a few of those books by the time Trump's term is over, documenting all the madness of the Trump White House. In the meantime, with Mueller's investigation getting closer and closer to the Oval Office, Trump needs his aides' loyalty more than ever. If he thinks they're willing to endure pain (and maybe jail) in order to protect him, he may be in for a surprise.