For the first time in months, Donald Trump has lost the lead in a major national poll, falling behind Senator Ted Cruz of Texas.

Trump took the lead in national GOP

surveys in July, surpassing former Florida Governor Jeb Bush. He has dominated the race since then, except for a period in the fall during Ben Carson’s short boomlet.

But the latest NBC/Wall Street Journal poll shows a significant shift: Cruz has the backing of 28 per cent of the Republican primary voters surveyed, with Trump at 26 per cent. Senator Marco Rubio of Florida, at 17 per cent, Governor John Kasich of Ohio at 11 per cent, Carson at 10 per cent and Bush at 4 per cent round out the field.

Primaries, of course, are fought out state-by-state, not in a single national ballot. But Trump’s support in the states so far has largely mirrored his national standing. Moreover, his steady lead in polls has been a major feature of his stump speech.

Any individual poll could prove to be a fluke. But the NBC/Wall Street Journal survey, conducted by two longtime pollsters, Republican Bill McInturff and Peter Hart, a Democrat, is one of the most highly regarded in the field, so the results are likely to attract considerable attention.

“When you see a number this different, it means you might be right on top of a shift in the campaign. What you don’t know yet is if the change is going to take place or if it is a momentary ‘pause’ before the numbers snap back into place,” McInturff said in a statement announcing the results.

The poll also showed a decline, by nine points since January, in the share of GOP voters who can see themselves supporting Trump, down to 56 per cent from 65 per cent. In hypothetical head-to-head matchups, Trump would trail Cruz 56 per cent to 40 per cent and Rubio 57 per cent to 41 per cent, the survey found.

The survey has a margin of error of plus or minus 4.9 percentage points.

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