The plunge in sales reflect the gains for Chinese EVs, boosted by the troubles at Tesla and the dislike of Musk among those unhappy about his support for conservative causes.

Tesla Inc. is in a sales slump, with deliveries of its electric vehicles on track to decline for the second full year in a row.

And Musk seemingly can’t let that go. “Physics sees through all lies perfectly,” Musk posted this week on his social-media platform X. The Tesla and SpaceX CEO’s political power in Washington—which just a few months ago seemed limitless —was always about proximity to the president.