New York - Donald Trump returned fire on fellow Republicans who had bombarded him with criticism over his proposed ban on all Muslims entering the US, hinting that he might renege on a pledge not to run as an independent candidate next year.
While many Republicans now consider Mr Trump a mortal threat to their hopes of winning back the White House, and possibly to keeping control of Congress, even worse for them than his winning the party's nomination for president would be a decision to go it alone.
A USA Today poll this week found that 68 percent of his current supporters would remain loyal to him if he forsook the Republican Party.
“I might consider that,” he said, appearing on ABC's morning talk show.
Earlier he posted Twitter messages highlighting that poll, as well as a CNN survey showing him further extending his lead in the critical state of New Hampshire. His 32 percent level of support there was up 6 percent since September.
The fall-out from Mr Trump's suggestion that the US close its borders to Muslims, following the massacre of 14 people in San Bernardino, California, by a couple - one of whom had pledged allegiance to Isis on Facebook - has sent shockwaves around the globe. In the US, it has cemented the impression of a Republican Party that has lost all control of its own efforts to regain the presidency, with Mr Trump basically going rogue.
Rival candidiate Jeb Bush said on Twitter that if Mr Trump were to quit the party, it would hand next year's presidential race to the Democrats.
“Continuing this path will put [Hillary Clinton] in the White House,” Mr Bush posted.
Mr Trump is preparing to visit a police conference in New Hampshire, and to visit Israel next month.
Meant to burnish his thoroughly threadbare foreign policy credentials, that trip now takes on quite a different complexion.
Pressure was growing on Israel's Prime Minister, Benjamin Netanyahu, to cancel a planned meeting with Mr Trump.
At least 37 Knesset members had last night signed a petition urging him to back out.
Mr Netanyahu distanced himself from Mr Trump on the issue of Muslim immigration.
“Prime Minister Netanyahu rejects Donald Trump's recent remarks about Muslims,” a statement? said.
“The State of Israel respects all religions and strictly guarantees the rights of all its citizens.”
Palestinian activists also voiced concern.
“Netanyahu wants to see a Republican, the more extreme the better, from his perspective,” Palestinian rights advocate Ali Abunimah told The Independent.
“It will be interesting to see if [Mr Trump] attempts to consolidate his base by adding extreme anti-Palestinian rhetoric to his anti-Muslim enticement in the US.”
Meanwhile, US Attorney General Loretta Lynch said there was no evidence the San Bernadino shooters were part of a wider terror conspiracy or that the husband, Syed Farook, was involved in an earlier plot to attack targets, as was reported on Wednesday.
“We do not have an indication that these two people were part of a larger cell,” Ms Lynch said in London.
“We do not have an indication that they were planning specific things beyond this attack.” FBI director James Comey revealed, however, the couple discussed an attack two years ago.
Mr Trump reacted to Time magazine's choice of Angela Merkel as its Person of the Year by tweeting: “I told you @TIME Magazine would never pick me... despite being the big favourite. They picked person who is ruining Germany.”
The Independent