Update: It’s worth noting that this isn’t an outlier. The RCP average of head-to-head polling between Trump and Clinton has Hillary up 6 points, 47.3/41. Over the last six months, Trump has only led in four polls out of thirty, and in his most recent two wins, his lead was within the margin of error.

Original post follows:

Last night, Donald Trump called on Republicans to unite behind him and declared that only he could defeat Hillary Clinton. A new NBC/WSJ poll out this morning disputes that claim — although the general election is still a long way off. Trump loses to both Hillary and Bernie Sanders by double-digit margins in this sample of 1200 registered voters, but Marco Rubio and Ted Cruz look much more competitive:

Hillary Clinton or Bernie Sanders would handily defeat Donald Trump in a general election match-up, while a clash between Clinton and Texas Sen. Ted Cruz or Florida Sen. Marco Rubio would be a toss-up, according to a new NBC News/Wall Street Journal poll.

The poll shows that Trump, who frequently boasts in interviews and campaign appearances that he would beat Clinton in November, would lose a one-on-one contest against her by double digits. In a head-to-head fight, Clinton gets the support of 51 percent of registered voters compared to 38 percent for the real estate mogul.

For Sanders, the margin of victory would be even greater, the poll shows.

The Vermont senator gets 55 percent support in a hypothetical two-person race against Trump, while the GOP front-runner would get just 37 percent.

For the record, Rubio ties Hillary at 46%. while Cruz trails within the margin of error, 45/47. The pollsters didn’t ask about head-to-head matchups against Sanders for either of the two Republican Senators, which is too bad, as a Sanders nomination is still not out of the realm of possibility.

Readers should consider a couple of caveats in this poll. First, the sample leans toward desiring a Democratic president, 46/42, asked prior to the candidate questions (the sample overall is D+6). Second, head-to-head polling at this stage still carries a lot of emotional freight that may well disappear after the conventions, or at least diminish significantly. If Trump wins the nomination, he will have months to shift his approach for the general election and test whether he’s right about building a large coalition of disaffected non-Republicans.

However, the favorability numbers show why Trump struggles against the two Democrats, at least at this stage. Hillary gets a 38/51, or -13 favorability rating, in this poll; Sanders has a +7 at 43/36. Rubio has a -11 at 28/39, likely the product of his fierce and personal attacks on Trump, but Cruz does worse with -18 at 27/45. Trump, however, gets only 25/64 for a -39 rating, by far the worst in the field. Trump also does worst among all candidates for potential support in a general election at 32/67 (although not that far behind Cruz and Rubio), and also worst among Republican primary voters for support for the nomination at 56/43.

Given that, it’s hardly surprising that Trump does poorly in a general pool of registered voters — now, anyway. Would that change once the GOP infighting stops and Republicans accept Trump as the nominee? Maybe, but at that point the media will likely become entirely hostile to Trump and probably a lot less generous about air time, too. If Trump didn’t adjust by organizing effectively on the ground — and there’s still time to do that, especially with the RNC’s efforts already in place — then those negatives would likely drive Trump’s chances into the slim or none category.