Rep. Andy Harris, chair of the ultra-conservative House Freedom Caucus, reiterated his threat that hardline Republicans will tank a key procedural vote on Trump's mega bill and stop the legislation’s progress dead in its tracks. The vote is expected within the hour, but could slide later.

"I am saddened to watch Elon Musk go completely "off the rails," essentially becoming a TRAIN WRECK over the past five weeks,' Trump wrote on social media.

President Donald Trump blasted Elon Musk’s bid to start a new political party, intensifying a feud between former allies and deepening investors’ concerns about implications for Tesla Inc. and other companies led by the world’s richest man.