WASHINGTON – President Donald Trump appeared to threaten the former head of the FBI on Twitter on Friday, warning the just-fired James Comey not to leak to the media.The president tweeted: “Comey better hope that there are no ‘tapes’ of our conversations before he starts leaking to the press!”It’s unclear whether the president was alluding to actual secret recordings, or making a casual remark. The president’s opponents immediately found Nixonian parallels, making comparisons to the White House tapes that fuelled the Watergate scandal.The administration only fed the intrigue. Later in the day, a solemn-sounding spokesman repeatedly shrugged off questions about whether the White House does, in fact, secretly tape the president’s meetings.“I’ve talked to the president. The president has nothing further to add on that,” Sean Spicer told the daily briefing.Democrats asked to know more.A lawmaker, Raja Krishnamoorthi, sent a letter to the White House attorney with two questions:— Do secret recordings exist?— If so, could the White House please provide copies of the president’s conversations with Comey; conversations about the hiring or firing of Russia-friendly former general Michael Flynn and the meeting this week with Russia’s ambassador and foreign minister?The president’s threat came in a series of frustrated morning tweets that called the Russia investigations a witch-hunt, threatened to cancel White House press briefings, accused the media of conveying fake news and lamented that people were making a big deal out of the occasional erroneous statement from his staff.The morning rant came after media pointed out contradictions in his story of the Comey firing.A main one was the notion peddled by the White House that the firing was a response to a suggestion from the deputy attorney general — which Trump has said isn’t true. He’s said he wanted Comey gone and would have fired him regardless.Another point of contention was whether the president received an assurance from Comey he was not being investigated. Trump says so. But now stories are appearing in multiple news reports, with details of a Comey-Trump dinner that contradict that assertion.Hence the context for the president warning Comey to keep quiet.The president is entering a legally dangerous area, said Nick Ackerman, an assistant Watergate prosecutor and former assistant U.S. attorney for New York. He referred to multiple reports about the Comey-Trump dinner, purporting to reflect Comey’s version.“What we’re really talking about is the potential obstruction of justice of an ongoing investigation,” Ackerman told MSNBC.“He invites the head of the FBI over for dinner — which in itself is probably inappropriate if they’re going to be talking about the Russian investigation. Then to demand loyalty from him is completely over the top.”Another expert said the threatening tweet might be legal. That’s because the definition of blackmail in U.S. law is unclear, said Yale law professor Steven Duke.“Our extortion statutes are extremely vague, leaving room at least for an argument that almost any threat is extortion,” Duke said. “Trump could claim that he was only trying to motivate Comey to tell the truth and he was not seeking to induce Comey to do anything other than remaining silent or telling the truth.”Duke said the more interesting question is why Trump keeps piling one deception atop another: “Trump knows there are no tapes of his conversations with Comey; that’s why he can falsely claim that Comey assured him that he was not under investigation.”Meanwhile, Trump’s opponents are starting to search his money trail.Lawmakers are increasingly focusing on Trump’s business relationships. They have asked for documents from the Treasury Department’s foreign money-laundering unit. That same unit fined Trump’s Taj Mahal casino $10 million in 2015 for long-standing, repeated, violations of money-laundering reporting rules.On Friday, Trump’s lawyers announced he had only minor financial dealings with Russia over the last 10 years. Yet, just a little more than 10 years ago, as he was making his latest financial comeback, Trump did several real-estate deals with a Russian formerly convicted of money-laundering.That falls just outside the period covered by his lawyers’ statement.