If the last state primary elections didn't settle matters for some Democrats, Barack Obama's powerful endorsement certainly did. Hillary Clinton is without doubt the party's presumptive presidential candidate, whether Bernie Sanders and some of his sulking supporters like it or not. Elizabeth Warren's additional backing for Hillary may make them feel better.

Let's hope so, and hope that in November, they and most other American voters will choose the former secretary of state over the serial-lying, bullying swindler of a Republican candidate. But one factor that still stands in Mrs. Clinton's way is the possibility that she may be indicted by the Justice Department, based on the FBI investigation of her private email server.

That investigation has been going on for nine months -- since last August.

Yet the last public word from FBI Director James Comey, which came a full month ago, is that he won't be rushed into making a decision on whether to recommend Mrs. Clinton's indictment -- something that could well decide who will be our next president. "I don't tether to any particular external deadline," Comey told reporters, "so I do feel the pressure to do it well and promptly, but as between the two, I always choose 'well'."

A month later, with Clinton's much-anticipated FBI interview still not even scheduled, that statement is thoroughly outdated. The president's enthusiastic endorsement, along with his plan to campaign with Mrs. Clinton and his statement that "I don't think there's ever been someone so qualified to hold this office," make it nearly impossible to believe that she's going to be charged with any crime.

After all, Attorney General Loretta Lynch is an Obama appointee and a Democrat who also served under President Clinton. If she and Director Comey, a Republican, had any thought of indicting Mrs. Clinton, the president would surely at least have known about it, and avoided enthusiastically supporting Clinton as his successor.

But the fact is the investigation is ongoing. What would happen if Mrs. Clinton were charged?

If she were indicted between now and the party's convention, beginning July 25, it would be devastating enough for the tens of millions of Democratic voters. Their party would be under extreme pressure to choose another candidate. Time would be short. But at least Democrats would have the advantage of a national convention to decide what to do and begin to reorganize.

However, if she were indicted after becoming the party's official nominee, matters would be infinitely worse for the Dems. Choosing another candidate long-distance would be much more complicated and a lot less democratic, and chances of winning would be further reduced by even less time to reorganize and campaign.

A third possibility would be worse not only for Democrats but for all Americans. If Mrs. Clinton were indicted after being elected, the whole country might be embroiled in one of the bloodiest political battles in American history, as to whether a president-elect or president should resign over the charges.

Besides which, if she wasn't already gone, she'd have to leave office if convicted, and quite possibly abandon the White House for the jailhouse. If you think American government and politics are a polarized mess now, imagine those last two scenarios!

Not to mention the fact that any of the above occurrences would greatly increase the catastrophic possibility of Donald Trump in the White House. A man who's never held elective or other government office, he's one of the least qualified major-party presidential candidates in American history. Besides which, he's correctly described by conservative legal scholars as a bigot who doesn't understand world or domestic affairs and poses a serious threat to the First Amendment. And he's a businessman who defrauds customers and doesn't pay his bills.

A vastly increased chance of Trump's election, and one or more of the other dire possibilities mentioned earlier, are on the table if AG Lynch and the FBI's Comey don't decide in the six weeks before the Democratic convention whether or not to indict Clinton.

Outside lawyers and scholars have weighed in with opinions on both sides, even though much of the evidence is unavailable to outsiders. The Libertarian Party's new vice presidential nominee, former Massachusetts governor William Weld, who once headed the Justice Department's criminal division, says there's no way prosecutors can prove criminal intent that he says is necessary to indict Clinton. But former attorney general Michael Mukasey argues she's almost certainly guilty at least of mishandling classified information and maybe also of gross negligence. That last could land her in jail for ten years.

Again, the president's blessing makes it very hard to believe that Secretary Clinton will be charged with any crime in connection with her private emails. But that ruling has to come from Ms. Lynch and Mr. Comey and they should make it right away, one way or the other.