Elon Musk's social media fight with President Trump over the budget bill this week threatens to have a larger impact.

A public feud between President Donald Trump and his on-again, off-again ally, billionaire Elon Musk, reignited this week after an apparent truce lasted less than a month.

Their escalating feud threatens critical parts of the billionaire’s business empire — and leaves Republican legislators caught in a tussle between the two.