Donald Trump will take office as president facing a tsunami of litigation over his business practices and personal behavior. He may have settled the fraud suits involving Trump University, but at least 75 other lawsuits are underway against him or his companies, according to USA Today. Its investigation found more than 3,500 lawsuits over the past three decades, ranging from contract disputes to real estate battles to harassment and discrimination claims.

In short, Mr. Trump could find himself in a near-constant stream of court fights while he tries to focus on running the country. Even in advance of any decisions, there is a degree of poetic justice here, since the scorched-earth approach has long been standard practice for Mr. Trump; as a businessman, he thrived on no-holds-barred legal conflict and hauled out the heavy artillery for even minor disputes. Less than three weeks before the election, he threatened to sue at least 11 women who had recently come forward with allegations that he sexually assaulted them.

Now consider all the potential conflicts of interest if this litigiousness should come to, or from, the Oval Office. What happens if there is litigation involving a building he leases from the federal government? Or if the Internal Revenue Service — an executive-branch agency — recommends civil or criminal penalties based on an audit of Mr. Trump’s taxes?

The Trump University lawsuits — two class actions filed in a San Diego federal court and a state fraud case brought by the New York attorney general, representing about 7,000 plaintiffs in all — show that these conflicts would not be limited to the federal government. Court documents revealed a dishonest operation that was marketed as a way for regular people to make lots of money by following Mr. Trump’s “secrets” to real estate investing.