The first serious poll taken since the Republican candidates' debate on the Fox Network last weekend found him still in the lead. His support seems not to have suffered from his aggressive attitude to a woman on the debate panel when she questioned his attitude to women, or the deeper hole he dug for himself later when he referred to blood coming from her "wherever".
Some of those who find his obnoxiousness entertaining must be giving him a vote in opinion polls but even they probably will hesitate to give him the vote that counts. The interesting question is, how much damage will he do to the Republican Party in the meantime?
None of the candidates on stage with him last weekend knew what to do about him, even though he alone had raised his hand when they were asked whether they might run independently if they did not get the party's nomination.
Former Florida Governor Jeb Bush, who looks the likely nominee at this early stage, said nothing against him until well after the debate. Florida Senator Marco Rubio, who appears to have what it takes, remained silent.
They all seemed much more haunted by Hillary Clinton, who may be the Democrats nominee next year. Mr Trump is said to be a financial contributor to Mrs Clinton's campaigns, but that probably means little. He told the debate he also donated to some of his rivals on stage and they looked sheepish.
All of them have a long way to go even to reach the first primaries in the new year. Right now their campaigns all need to raise money, all except Mr Trump obviously. He will be enjoying himself immensely, saying what he likes, causing offence, poking fun at political correctness because he alone can afford to.
But finally elections are always about judgment. People generally vote for candidates whose judgment is sound. Platforms, policies, promises quite rightly count for less than what a candidate says and does in response to challenges and difficulties that arise in an election campaign.
The US presidential election campaign seems to get longer every time it comes around.
Mr Trump's ego and bank account might last the distance but nobody seriously expects him to be the next President. If he runs as an independent, at most he could spoil the Republicans' chances. Since they would need to attack him at that point, they might do better to go at him now.
