A group of 13 House Republicans—12 of whom backed Trump’s policy bill, and several whose campaigns were backed heavily by Elon Musk—urged the Senate to make changes to the clean energy tax credit provision that Tesla Energy has also advocated for in a letter Friday,

Less than a week later, their potent political alliance met a dramatic end Thursday when the men attacked each other with blistering epithets.

Shares of Elon Musk’s electric vehicle maker plunged more than 14% in a stunning wipeout as investors dumped holdings amid a bitter war of words between the president and the world’s richest man.