President Donald Trump is right, so far: the sprawling investigation by special counsel Robert Mueller hasn’t shown that Trump himself did anything wrong. It may never.

But it is beginning to show that some of Trump’s top advisers were shady characters who had no business helping run a U.S. presidential campaign. Should Trump have known that? Unclear. But Trump’s history as a candidate, and now as commander-in-chief, increasingly reveals a boss who prizes loyalty over competence and risks his own success through subpar hires.

Mueller has indicted Trump’s former campaign chairman, Paul Manafort, and Manafort’s partner, Richard Gates, on charges related to foreign business dealings that may have involved money laundering. Mueller has made no connection between those charges and Manafort’s role in the Trump campaign.

Another Trump campaign adviser, George Papadopoulos, has pled guilty to lying to the FBI about contacts he had with Russian officials while working on the Trump campaign. As part of that plea deal, Papadpoulus appears to be cooperating with prosecutors, which means he could provide information leading to charges against other Trump campaign officials. That’s bad news for Trump all around.

It’s worth pointing out that a few bad apples on an entire presidential campaign staff is more the norm than the exception in American politics. Scoundrels exploit politics for personal gain, sometimes illegally, just as they do in business, sports, entertainment and probably every other sector of the economy.

Trump’s advisers are loyal but unfit for the job

What’s different about Trump is his willingness to rely on senior advisers who might be loyal, but who are also weak or compromised in ways that make them ineffective at best and a major liability at worst. Trump’s first national security adviser, Michael Flynn, resigned after less than a month because he lied to Vice President Mike Pence about details of his meetings with the Russian ambassador to the United States. Flynn was appointed to run the Defense Intelligence Agency in 2014, but was essentially fired two years later amid questions about his competence. President Barack Obama advised Trump not to bring Flynn into his administration. Trump should have listened, but he didn’t, and Flynn’s shocking early departure became one of Trump’s first major embarrassments.

Trump’s first Health and Human Services Secretary, Tom Price, resigned in September following revelations that he needlessly flew around the country on private military jets, at a cost of hundreds of thousands of dollars. Trump should have known Price was sketchy, given multiple reports of questionable stock trades he made involving companies that could have benefited from the actions of House committees Price was an influential member of. Was Price the best guy to run a large part of the government? No. But he turned out to be Trump’s guy, until petty greed sank him.