No, Hillary Clinton isn’t going to ‘clinch the nomination’ tomorrow. Here’s why.

News organizations will face an important decision when the polls close Tuesday night in New Jersey.

If all goes as expected and Hillary Clinton wins even close to a majority of the 126 delegates up for grabs, journalists will make a choice, more or less, between two possible headlines:

Clinton Clinches Nomination

Clinton Wins New Jersey

There’s no question that headline No. 1 makes the bigger splash. There’s also no question, at least in my mind, that journalists should go with something closer to headline No. 2.

The argument for No. 1 goes like this: With 2,383 delegates needed for the nomination, New Jersey’s delegates will likely put Clinton over the top as long as you count the 548 superdelegates who have committed to support her.

My argument for headline No. 2 (or something more nuanced shy of No. 1) goes like this: Since those 548 superdelegates won’t actually cast their votes until the convention in July, it’s premature for journalists to act as if they have, in fact, already voted.

Clinton’s current overwhelming support among superdelegates (Sanders has commitments from only 46 of them) should by all means be part of Tuesday night’s story. But it should not be used to support declarations like Clinton clinching, crossing the threshold or any other lingo suggesting it’s all over.

The social media debate on the headline question has been vigorous, fueled in part by claims of media bias for and against both candidates.

I base my argument on a non-partisan journalistic principle: Report what you know.

Chris Matthews touched off the debate on his Hardball show May 23 with this comment to Sanders campaign manager Jeff Weaver:

I’m told by the experts on numbers around here at NBC and elsewhere that come June 7 the day of the California primary…at 8 o'clock that night, Eastern Time, the networks will be prepared — including this one — to announce that Hillary Clinton has now gotten over the top, that she will have won the nomination in numbers. It’s done.

Matthews asked Weaver whether such a declaration hours before the polls close that night in California and other western states would depress turnout more among Sanders supporters or those backing Hillary Clinton.

“It will depress turnout on both sides,” Weaver answered. “Whenever there’s no contest you get depressed turnout.” (That reality has prompted Congress to debate uniform poll closings for years without resolution.)

You’d expect Weaver to object to what Matthews characterized as network plans to award the nomination to Clinton. But his point is worth considering without regard to his role in Sanders’ camp.

As he argued that declaring Clinton the presumptive nominee would be “an inaccurate description of the state of the race,” Matthews interjected: “So the networks will be wrong?”

“Yes,” Weaver responded. “All we have from superdelegates is essentially a poll.”

If you’re anything like me and have failed to keep track of exactly how the Democratic Party apportions delegates and superdelegates, here’s a primer drawn from a Feb. 26 Washington Post story by D. Stephen Voss:

The Democratic Party allocated 4,763 delegate slots for its 2016 national convention…Voters select more than 4,000 of those delegates, choosing them in state primaries and caucuses according to which candidates the delegates pledged to support. But the remaining 15 percent of the delegate seats, or 712 in total, were set aside for Democrats identified by the positions they hold (or used to hold) within the party… These so-called superdelegates are not required to support a particular candidate. They may ignore voters’ preferences if they wish. Instead, they select a candidate using their own judgment, a choice they may (or may not) signal in advance by issuing an endorsement.

In a piece published May 24, Harry Enten of FiveThirtyEight noted that his organization has refrained from including superdelegates in its tracker because delegates could still change their minds — especially if Sanders were to win a majority of elected delegates. With that scenario now a virtual impossibility, he suggested that Tuesday night might be the time to assume Clinton will hold onto enough superdelegates “to clinch the nomination.”

Since when should journalists be drawing conclusions based on assumptions?

Sanders supporters offer a variety of scenarios that might swing superdelegate support their way: More damning revelations about Clinton’s email problems, polls showing Sanders as a stronger candidate against presumptive Republican nominee Donald Trump, etc.

Clinton backers have as many rebuttals as the Sanders people have scenarios, of course. Neither am I discounting how stunning it would be if the superdelegates — the very embodiment of the Democratic Party establishment — were to end up handing the nomination to the most anti-establishment candidate in years.

Almost as stunning as an outrageous outlier like Donald Trump winning the Republican nomination.

Here’s the real question that journalists need to humble themselves and ask Tuesday night: Who knows what might happen between now and July 25 when the Democratic National Convention opens in Philadelphia?

Especially in an election year like this one, the answer is clear: Nobody knows!

As more and more campaign coverage devolves into unknowable guesswork — speculation about the horserace — journalistic principles like reporting what you actually know have faded into the background.

Here’s an opportunity — an obligation, I’d argue — for news organizations to return those principles to the fore and stick to what they know.