Yesterday the president tweeted a lot, even for him. In one hour this morning, he tweeted or retweeted 52 times. By the end of the day, he had averaged a tweet every 7.5 minutes. None of the tweets mentioned the almost 80,000 Americans who have died from Covid-19 or any plans for addressing the pandemic.

Trump appears to be upset about the recent prominence of former President Barack Obama in the news. On Friday, a tape of Obama talking to about 3000 former staffers leaked. In it, the former President expressed dismay over the Justice Department’s decision to drop the case against former National Security Advisor Michael Flynn. He warned that “our basic understanding of the rule of law is at risk,” and noted that once a nation abandons the rule of law the destruction of its legal government is often rapid. Obama also called Trump’s response to the coronavirus pandemic an “absolute chaotic disaster.” Since leaks from Obama officials are scarcer than hen’s teeth, we have to assume this leak was deliberate.

Trump’s morning tweetstorm makes the president seem preoccupied with Obama. He seems tied to the idea that the FBI was investigating the links of some of the people on his campaign to Russia, a situation he called “OBAMAGATE!” on Twitter this morning. He retweeted the claim by conservative talk show host Buck Sexton that Obama “used his last weeks in office to target incoming officials and sabotage the new administration.” Trump added to the tweet “The biggest political crime in American history, by far!” He also retweeted from an account that, at the time, had 43 followers: “Unless people are indited [sic] and put in prison the corruption will continue. People will continue to run with fake news and conspiracies until they are shown individuals being handcuffed and prosecuted. Its [sic] also time to fire people from the FBI, CIA, DOJ, DNI #CleanHouse.”

Trump’s power struggle against any oversight of his presidency is approaching a critical moment. On Tuesday, the Supreme Court will hear arguments about whether Congress or state prosecutors can investigate him for potential wrongdoing. There are three different cases, which involve two issues.

The first two cases have to do with congressional oversight of the president. The House Oversight Committee is investigating Trump’s finances, following his former lawyer and fixer Michael Cohen’s testimony last year about a $130,000 payment to adult film actress Stormy Daniels to keep her quiet about their sexual relations, a payment that should have been disclosed. Cohen also testified that Trump routinely exaggerated his assets when getting loans and deflated them when it came time to pay taxes. A year ago, in April 2019, the committee issued a subpoena to the president’s accounting firm, Mazars USA, seeking the relevant financial information.

The second case is similar. House committees have subpoenaed financial records from Capital One and Deutsche Bank to investigate the “questionable financing” of Trump’s businesses before his presidency, to see whether “any foreign actor has sought to compromise or holds leverage, financial or otherwise, over Donald Trump, his family, his business, or his associates.” (Remember, in 2008, Donald Trump, Jr. famously said at a New York real-estate conference “In terms of high-end product influx into the US, Russians make up a pretty disproportionate cross-section of a lot of our assets…. We see a lot of money pouring in from Russia.”)

The third case involves the question of whether a president can be investigated for violating state law. Cyrus Vance, Jr., the Manhattan district attorney, is also investigating hush money Trump paid to Daniels and to another woman, Karen McDougal, a Playboy model who also says she had an affair with Trump. Vance and state prosecutors have subpoenaed several years of tax documents from Mazars USA concerning both Trump himself and his business, the Trump Organization.

An internal memo adopted by the Justice Department’s Office of Legal Counsel in 1973, during the Watergate crisis, says that a sitting president cannot be indicted for a crime. This is why Special Counsel Robert Mueller, who was operating within the Justice Department, never entertained the question of whether the president had committed a crime: Mueller never considered that part of his charge.

The question at stake before the Supreme Court this week is not whether a president can be indicted, but whether he can even be investigated. Trump’s lawyers maintain the answer is no. They say that congressional committees can only investigate subjects about which Congress can make laws; they can’t investigate whether the president broke the law because that would violate our system of the separation of powers. States can’t investigate the president because they can abuse that power, gumming up a president’s schedule so that he cannot perform his duties. More, Trump’s lawyers are saying that not only does the president enjoy immunity from oversight, so do his businesses.

Every court that has heard these cases has sided against the president, in favor of oversight.

There is also precedent that bears on these questions. In 1974, the Supreme Court ruled unanimously that President Richard Nixon had to hand over to a special prosecutor tapes he had recorded in the Oval Office with advisors about the Watergate scandal. Nixon did so and resigned shortly thereafter. In 1997, the Supreme Court ruled unanimously that President Bill Clinton did not have immunity from civil litigation for events that happened before he took office and that he must respond to a harassment suit by former Arkansas state employee Paula Jones. This case led to the Monica Lewinsky scandal.

On its face, it seems like the court’s decision should be clear, as lawyer George Conway, who ghostwrote briefs for Paula Jones, explained Friday in the Washington Post. But this Supreme Court has indicated a willingness to break precedent in favor of a strong executive. Still, there is yet one more twist in this saga: because of the pandemic, the arguments will be streamed live, and open for the public to tune in, so it is likely the arguments on both sides will be in the news.

The importance of the upcoming Supreme Court arguments might have had something to do with today’s tweetstorm.

Heather Cox Richardson is Professor of History, Boston College. This was originally published in her Substack newsletter on May 10 2020. Subscribe for free here.