8:03 AM PT -- The White House just came out and blasted Elon's support of this tweet, with a spokesperson saying ... "It is unacceptable to repeat the hideous lie behind the most fatal act of Antisemitism in American history at any time, let alone one month after the deadliest day for the Jewish people since the Holocaust."

They continue, "Like President Biden said weeks ago memorializing the victims of the Pittsburgh Synagogue shooting, the October 7 'devastating atrocity has brought to the surface painful memories left by millennia of Antisemitism.'

The spokesperson finishes by saying, "We condemn this abhorrent promotion of Antisemitic and racist hate in the strongest terms, which runs against our core values as Americans."

Elon Musk is being accused of antisemitism after he said there was "truth" in a post that suggested Jews hate white people -- and it's now snowballing into a very costly problem.

The Tesla chief has a bit of a fire going down at his Twitter/X house right now -- and it's of his own doing ... this after he responded to a tweet that floated the idea that Jewish people spew the kind of ugly racist rhetoric that's so often thrown in their direction.

The OG Twitter user was responding to a video that was calling for an end to antisemitism, writing ... "Jewish communities have been pushing the exact kind of dialectical hatred against whites that they claim to want people to stop using against them."

He added, "I'm deeply disinterested in giving the tiniest s*** now about western Jewish populations coming to the disturbing realization that those hordes of minorities that support flooding their country don't exactly like them too much."

Elon replied, "You have said the actual truth." His apparent cosign of this sentiment -- which has widely been labeled as antisemitic -- is now causing backlash against EM ... with some saying he's supporting Jew-hating propaganda here. Of course, he's pushing back on that.

In subsequent tweets/replies, Elon has tried deflecting his criticism to orgs like the ADL -- but it seems the damage might be done ... 'cause one of his biggest advertisers is bailing.

Media Matters reported Wednesday that IBM had paused ads on Musk's platform -- this after some of their content was apparently starting to show up next to tweets promoting Nazis ... something the company saw and immediately backed away from.

The fact Elon had said what he said just a day earlier was lost on no one either -- but he's suggesting this all a smear campaign, calling MM an "evil organization."